Produced by Steve Solomon.  HTML version by Al Haines.









Cascadia Gardening Series

Gardening Without Irrigation: or without much, anyway

Steve Solomon



CONTENTS


Chapter

   1  Predictably Rainless Summers
   2  Water-Wise Gardening Science
   3  Helping Plants to Need Less Irrigation
   4  Water-Wise Gardening Year-Round
   5  How to Grow It with Less Irrigation: A-Z
   6  My Own Garden Plan
   7  The Backyard




Introduction

Starting a New Gardening Era


First, you should know why a maritime Northwest raised-bed gardener
named Steve Solomon became worried about his dependence on
irrigation.

I'm from Michigan. I moved to Lorane, Oregon, in April 1978 and
homesteaded on 5 acres in what I thought at the time was a cool,
showery green valley of liquid sunshine and rainbows. I intended to
put in a big garden and grow as much of my own food as possible.

Two months later, in June, just as my garden began needing water, my
so-called 15-gallon-per-minute well began to falter, yielding less
and less with each passing week. By August it delivered about 3
gallons per minute. Fortunately, I wasn't faced with a completely
dry well or one that had shrunk to below 1 gallon per minute, as I
soon discovered many of my neighbors were cursed with. Three gallons
per minute won't supply a fan nozzle or even a common impulse
sprinkler, but I could still sustain my big raised-bed garden by
watering all night, five or six nights a week, with a single, 2-1/2
gallon-per-minute sprinkler that I moved from place to place.

I had repeatedly read that gardening in raised beds was the most
productive vegetable growing method, required the least work, and
was the most water-efficient system ever known. So, without adequate
irrigation, I would have concluded that food self-sufficiency on my
homestead was not possible. In late September of that first year, I
could still run that single sprinkler. What a relief not to have
invested every last cent in land that couldn't feed us.

For many succeeding years at Lorane, I raised lots of organically
grown food on densely planted raised beds, but the realities of
being a country gardener continued to remind me of how tenuous my
irrigation supply actually was. We country folks have to be
self-reliant: I am my own sanitation department, I maintain my own
800-foot-long driveway, the septic system puts me in the sewage
business. A long, long response time to my 911 call means I'm my own
self-defense force. And I'm my own water department.

Without regular and heavy watering during high summer, dense stands
of vegetables become stunted in a matter of days. Pump failure has
brought my raised-bed garden close to that several times. Before my
frantic efforts got the water flowing again, I could feel the
stressed-out garden screaming like a hungry baby.

As I came to understand our climate, I began to wonder about
_complete_ food self-sufficiency. How did the early pioneers
irrigate their vegetables? There probably aren't more than a
thousand homestead sites in the entire maritime Northwest with
gravity water. Hand pumping into hand-carried buckets is impractical
and extremely tedious. Wind-powered pumps are expensive and have
severe limits.

The combination of dependably rainless summers, the realities of
self-sufficient living, and my homestead's poor well turned out to
be an opportunity. For I continued wondering about gardens and
water, and discovered a method for growing a lush, productive
vegetable garden on deep soil with little or no irrigation, in a
climate that reliably provides 8 to 12 virtually dry weeks every
summer.


Gardening with Less Irrigation

Being a garden writer, I was on the receiving end of quite a bit of
local lore. I had heard of someone growing unirrigated carrots on
sandy soil in southern Oregon by sowing early and spacing the roots
1 foot apart in rows 4 feet apart. The carrots were reputed to grow
to enormous sizes, and the overall yield in pounds per square foot
occupied by the crop was not as low as one might think. I read that
Native Americans in the Southwest grew remarkable desert gardens
with little or no water. And that Native South Americans in the
highlands of Peru and Bolivia grow food crops in a land with 8 to 12
inches of rainfall. So I had to wonder what our own pioneers did.

In 1987, we moved 50 miles south, to a much better homestead with
more acreage and an abundant well. Ironically, only then did I grow
my first summertime vegetable without irrigation. Being a low-key
survivalist at heart, I was working at growing my own seeds. The
main danger to attaining good germination is in repeatedly
moistening developing seed. So, in early March 1988, I moved six
winter-surviving savoy cabbage plants far beyond the irrigated soil
of my raised-bed vegetable garden. I transplanted them 4 feet apart
because blooming brassicas make huge sprays of flower stalks. I did
not plan to water these plants at all, since cabbage seed forms
during May and dries down during June as the soil naturally dries
out.

That is just what happened. Except that one plant did something a
little unusual, though not unheard of. Instead of completely going
into bloom and then dying after setting a massive load of seed, this
plant also threw a vegetative bud that grew a whole new cabbage
among the seed stalks.

With increasing excitement I watched this head grow steadily larger
through the hottest and driest summer I had ever experienced.
Realizing I was witnessing revelation, I gave the plant absolutely
no water, though I did hoe out the weeds around it after I cut the
seed stalks. I harvested the unexpected lesson at the end of
September. The cabbage weighed in at 6 or 7 pounds and was sweet and
tender.

Up to that time, all my gardening had been on thoroughly and
uniformly watered raised beds. Now I saw that elbow room might be
the key to gardening with little or no irrigating, so I began
looking for more information about dry gardening and soil/water
physics. In spring 1989, I tilled four widely separated, unirrigated
experimental rows in which I tested an assortment of vegetable
species spaced far apart in the row. Out of curiosity I decided to
use absolutely no water at all, not even to sprinkle the seeds to
get them germinating.

I sowed a bit of kale, savoy cabbage, Purple Sprouting broccoli,
carrots, beets, parsnips, parsley, endive, dry beans, potatoes,
French sorrel, and a couple of field cornstalks. I also tested one
compact bush (determinate) and one sprawling (indeterminate) tomato
plant. Many of these vegetables grew surprisingly well. I ate
unwatered tomatoes July through September; kale, cabbages, parsley,
and root crops fed us during the winter. The Purple Sprouting
broccoli bloomed abundantly the next March.

In terms of quality, all the harvest was acceptable. The root
vegetables were far larger but only a little bit tougher and quite a
bit sweeter than usual. The potatoes yielded less than I'd been used
to and had thicker than usual skin, but also had a better flavor and
kept well through the winter.

The following year I grew two parallel gardens. One, my "insurance
garden," was thoroughly irrigated, guaranteeing we would have plenty
to eat. Another experimental garden of equal size was entirely
unirrigated. There I tested larger plots of species that I hoped
could grow through a rainless summer.

By July, growth on some species had slowed to a crawl and they
looked a little gnarly. Wondering if a hidden cause of what appeared
to be moisture stress might actually be nutrient deficiencies, I
tried spraying liquid fertilizer directly on these gnarly leaves, a
practice called foliar feeding. It helped greatly because, I
reasoned, most fertility is located in the topsoil, and when it gets
dry the plants draw on subsoil moisture, so surface nutrients,
though still present in the dry soil, become unobtainable. That
being so, I reasoned that some of these species might do even better
if they had just a little fertilized water. So I improvised a simple
drip system and metered out 4 or 5 gallons of liquid fertilizer to
some of the plants in late July and four gallons more in August. To
some species, extra fertilized water (what I call "fertigation")
hardly made any difference at all. But unirrigated winter squash
vines, which were small and scraggly and yielded about 15 pounds of
food, grew more lushly when given a few 5-gallon,
fertilizer-fortified assists and yielded 50 pounds. Thirty-five
pounds of squash for 25 extra gallons of water and a bit of extra
nutrition is a pretty good exchange in my book.

The next year I integrated all this new information into just one
garden. Water-loving species like lettuce and celery were grown
through the summer on a large, thoroughly irrigated raised bed. The
rest of the garden was given no irrigation at all or minimally
metered-out fertigations. Some unirrigated crops were foliar fed
weekly.

Everything worked in 1991! And I found still other species that I
could grow surprisingly well on surprisingly small amounts of
water[--]or none at all. So, the next year, 1992, I set up a
sprinkler system to water the intensive raised bed and used the
overspray to support species that grew better with some moisture
supplementation; I continued using my improvised drip system to help
still others, while keeping a large section of the garden entirely
unwatered. And at the end of that summer I wrote this book.

What follows is not mere theory, not something I read about or saw
others do. These techniques are tested and workable. The
next-to-last chapter of this book contains a complete plan of my
1992 garden with explanations and discussion of the reasoning behind
it.

In _Water-Wise Vegetables_ I assume that my readers already are
growing food (probably on raised beds), already know how to adjust
their gardening to this region's climate, and know how to garden
with irrigation. If you don't have this background I suggest you
read my other garden book, _Growing Vegetables West of the
Cascades,_ (Sasquatch Books, 1989).

Steve Solomon




Chapter 1

Predictably Rainless Summers


In the eastern United States, summertime rainfall can support
gardens without irrigation but is just irregular enough to be
worrisome. West of the Cascades we go into the summer growing season
certain we must water regularly.

My own many-times-revised book _Growing Vegetables West of the
Cascades_ correctly emphasized that moisture-stressed vegetables
suffer greatly. Because I had not yet noticed how plant spacing
affects soil moisture loss, in that book I stated a half-truth as
law: Soil moisture loss averages 1-1/2 inches per week during
summer.

This figure is generally true for raised-bed gardens west of the
Cascades, so I recommended adding 1 1/2 inches of water each week
and even more during really hot weather.


  Summertime Rainfall West of the Cascades (in inches)*

  Location         April    May    June    July    Aug.    Sept.    Oct.

  Eureka, CA        3.0     2.1     0.7     0.1     0.3     0.7     3.2
  Medford, OR       1.0     1.4     0.98    0.3     0.3     0.6     2.1
  Eugene, OR        2.3     2.1     1.3     0.3     0.6     1.3     4.0
  Portland, OR      2.2     2.1     1.6     0.5     0.8     1.6     3.6
  Astoria, OR       4.6     2.7     2.5     1.0     1.5     2.8     6.8
  Olympia, WA       3.1     1.9     1.6     0.7     1.2     2.1     5.3
  Seattle, WA       2.4     1.7     1.6     0.8     1.0     2.1     4.0
  Bellingham, WA    2.3     1.8     1.9     1.0     1.1     2.0     3.7
  Vancouver, BC     3.3     2.8     2.5     1.2     1.7     3.6     5.8
  Victoria, BC      1.2     1.0     0.9     0.4     0.6     1.5     2.8

  *Source: Van der Leeden et al., _The Water Encyclopedia,_ 2nd ed.,
  (Chelsea, Mich.: Lewis Publishers, 1990).


Defined scientifically, drought is not lack of rain. It is a dry
soil condition in which plant growth slows or stops and plant
survival may be threatened. The earth loses water when wind blows,
when sun shines, when air temperature is high, and when humidity is
low. Of all these factors, air temperature most affects soil
moisture loss.


  Daily Maximum Temperature (F)*

  July/August     Average

  Eureka, CA        61
  Medford, OR       89
  Eugene, OR        82
  Astoria, OR       68
  Olympia, WA       78
  Seattle, WA       75
  Bellingham, WA    74
  Vancouver, BC     73
  Victoria, BC      68

  *Source: The Water Encyclopedia.


The kind of vegetation growing on a particular plot and its density
have even more to do with soil moisture loss than temperature or
humidity or wind speed. And, surprising as it might seem, bare soil
may not lose much moisture at all. I now know it is next to
impossible to anticipate moisture loss from soil without first
specifying the vegetation there. Evaporation from a large body of
water, however, is mainly determined by weather, so reservoir
evaporation measurements serve as a rough gauge of anticipated soil
moisture loss.


  Evaporation from Reservoirs (inches per month)*

  Location        April    May    June    July    Aug.    Sept.    Oct.

  Seattle, WA      2.1     2.7     3.4     3.9     3.4     2.6     1.6
  Baker, OR        2.5     3.4     4.4     6.9     7.3     4.9     2.9
  Sacramento, CA   3.6     5.0     7.1     8.9     8.6     7.1     4.8

  *Source: _The Water Encyclopedia_


From May through September during a normal year, a reservoir near
Seattle loses about 16 inches of water by evaporation. The next
chart shows how much water farmers expect to use to support
conventional agriculture in various parts of the West. Comparing
this data for Seattle with the estimates based on reservoir
evaporation shows pretty good agreement. I include data for Umatilla
and Yakima to show that much larger quantities of irrigation water
are needed in really hot, arid places like Baker or Sacramento.


  Estimated Irrigation Requirements:
  During Entire Growing Season (in inches)*

  Location                            Duration         Amount

  Umatilla/Yakama Valley              April-October      30
  Willamette Valley                   May-September      16
  Puget Sound                         May-September      14
  Upper Rogue/Upper Umpqua Valley     March-September    18
  Lower Rogue/Lower Coquille Valley   May-September      11
  NW California                       April-October      17

  *Source: _The Water Encyclopedia_

In our region, gardens lose far more water than they get from
rainfall during the summer growing season. At first glance, it seems
impossible to garden without irrigation west of the Cascades. But
there is water already present in the soil when the gardening season
begins. By creatively using and conserving this moisture, some
maritime Northwest gardeners can go through an entire summer without
irrigating very much, and with some crops, irrigating not at all.




Chapter 2

Water-Wise Gardening Science


Plants Are Water

Like all other carbon-based life forms on earth, plants conduct
their chemical processes in a water solution. Every substance that
plants transport is dissolved in water. When insoluble starches and
oils are required for plant energy, enzymes change them back into
water-soluble sugars for movement to other locations. Even cellulose
and lignin, insoluble structural materials that plants cannot
convert back into soluble materials, are made from molecules that
once were in solution.

Water is so essential that when a plant can no longer absorb as much
water as it is losing, it wilts in self-defense. The drooping leaves
transpire (evaporate) less moisture because the sun glances off
them. Some weeds can wilt temporarily and resume vigorous growth as
soon as their water balance is restored. But most vegetable species
aren't as tough-moisture stressed vegetables may survive, but once
stressed, the quality of their yield usually drops markedly.

Yet in deep, open soil west of the Cascades, most vegetable species
may be grown quite successfully with very little or no supplementary
irrigation and without mulching, because they're capable of being
supplied entirely by water already stored in the soil.


Soil's Water-Holding Capacity

Soil is capable of holding on to quite a bit of water, mostly by
adhesion. For example, I'm sure that at one time or another you have
picked up a wet stone from a river or by the sea. A thin film of
water clings to its surface. This is adhesion. The more surface area
there is, the greater the amount of moisture that can be held by
adhesion. If we crushed that stone into dust, we would greatly
increase the amount of water that could adhere to the original
material. Clay particles, it should be noted, are so small that
clay's ability to hold water is not as great as its mathematically
computed surface area would indicate.


  Surface Area of One Gram of Soil Particles

  Particle type      Diameter of      Number of
                     particles        particles     Surface area
                     in mm             per gm          in sq. cm.

  Very coarse sand   2.00-1.00                 90            11
  Coarse sand        1.00-0.50                720            23
  Medium sand        0.50-0.25              5,700            45
  Fine sand          0.25-0.10             46,000            91
  Very fine sand     0.10-0.05            772,000           227
  Silt               0.05-0.002         5,776,000           454
  Clay Below         0.002         90,260,853,000     8,000,000

  Source: Foth, Henry D., _Fundamentals of Soil Science,_ 8th ed.
          (New York: John Wylie & Sons, 1990).


This direct relationship between particle size, surface area, and
water-holding capacity is so essential to understanding plant growth
that the surface areas presented by various sizes of soil particles
have been calculated. Soils are not composed of a single size of
particle. If the mix is primarily sand, we call it a sandy soil. If
the mix is primarily clay, we call it a clay soil. If the soil is a
relatively equal mix of all three, containing no more than 35
percent clay, we call it a loam.


  Available Moisture (inches of water per foot of soil)

  Soil Texture     Average Amount

  Very coarse sand      0.5
  Coarse sand           0.7
  Sandy                 1.0
  Sandy loam            1.4
  Loam                  2.0
  Clay loam             2.3
  Silty clay            2.5
  Clay                  2.7

  Source: _Fundamentals of Soil Science_.


Adhering water films can vary greatly in thickness. But if the water
molecules adhering to a soil particle become too thick, the force of
adhesion becomes too weak to resist the force of gravity, and some
water flows deeper into the soil. When water films are relatively
thick the soil feels wet and plant roots can easily absorb moisture.
"Field capacity" is the term describing soil particles holding all
the water they can against the force of gravity.

At the other extreme, the thinner the water films become, the more
tightly they adhere and the drier the earth feels. At some degree of
desiccation, roots are no longer forceful enough to draw on soil
moisture as fast as the plants are transpiring. This condition is
called the "wilting point." The term "available moisture" refers to
the difference between field capacity and the amount of moisture
left after the plants have died.

Clayey soil can provide plants with three times as much available
water as sand, six times as much as a very coarse sandy soil. It
might seem logical to conclude that a clayey garden would be the
most drought resistant. But there's more to it. For some crops, deep
sandy loams can provide just about as much usable moisture as clays.
Sandy soils usually allow more extensive root development, so a
plant with a naturally aggressive and deep root system may be able
to occupy a much larger volume of sandy loam, ultimately coming up
with more moisture than it could obtain from a heavy, airless clay.
And sandy loams often have a clayey, moisture-rich subsoil.

_Because of this interplay of factors, how much available water your
own unique garden soil is actually capable of providing and how much
you will have to supplement it with irrigation can only be
discovered by trial._


How Soil Loses Water

Suppose we tilled a plot about April 1 and then measured soil
moisture loss until October. Because plants growing around the edge
might extend roots into our test plot and extract moisture, we'll
make our tilled area 50 feet by 50 feet and make all our
measurements in the center. And let's locate this imaginary plot in
full sun on flat, uniform soil. And let's plant absolutely nothing
in this bare earth. And all season let's rigorously hoe out every
weed while it is still very tiny.

Let's also suppose it's been a typical maritime Northwest rainy
winter, so on April 1 the soil is at field capacity, holding all the
moisture it can. From early April until well into September the hot
sun will beat down on this bare plot. Our summer rains generally
come in insignificant installments and do not penetrate deeply; all
of the rain quickly evaporates from the surface few inches without
recharging deeper layers. Most readers would reason that a soil
moisture measurement taken 6 inches down on September 1, should show
very little water left. One foot down seems like it should be just
as dry, and in fact, most gardeners would expect that there would be
very little water found in the soil until we got down quite a few
feet if there were several feet of soil.

But that is not what happens! The hot sun does dry out the surface
inches, but if we dig down 6 inches or so there will be almost as
much water present in September as there was in April. Bare earth
does not lose much water at all. _Once a thin surface layer is
completely desiccated, be it loose or compacted, virtually no
further loss of moisture can occur._

The only soils that continue to dry out when bare are certain kinds
of very heavy clays that form deep cracks. These ever-deepening
openings allow atmospheric air to freely evaporate additional
moisture. But if the cracks are filled with dust by surface
cultivation, even this soil type ceases to lose water.

Soil functions as our bank account, holding available water in
storage. In our climate soil is inevitably charged to capacity by
winter rains, and then all summer growing plants make heavy
withdrawals. But hot sun and wind working directly on soil don't
remove much water; that is caused by hot sun and wind working on
plant leaves, making them transpire moisture drawn from the earth
through their root systems. Plants desiccate soil to the ultimate
depth and lateral extent of their rooting ability, and then some.
The size of vegetable root systems is greater than most gardeners
would think. The amount of moisture potentially available to sustain
vegetable growth is also greater than most gardeners think.

Rain and irrigation are not the only ways to replace soil moisture.
If the soil body is deep, water will gradually come up from below
the root zone by capillarity. Capillarity works by the very same
force of adhesion that makes moisture stick to a soil particle. A
column of water in a vertical tube (like a thin straw) adheres to
the tube's inner surfaces. This adhesion tends to lift the edges of
the column of water. As the tube's diameter becomes smaller the
amount of lift becomes greater. Soil particles form interconnected
pores that allow an inefficient capillary flow, recharging dry soil
above. However, the drier soil becomes, the less effective capillary
flow becomes. _That is why a thoroughly desiccated surface layer
only a few inches thick acts as a powerful mulch._

Industrial farming and modern gardening tend to discount the
replacement of surface moisture by capillarity, considering this
flow an insignificant factor compared with the moisture needs of
crops. But conventional agriculture focuses on maximized yields
through high plant densities. Capillarity is too slow to support
dense crop stands where numerous root systems are competing, but
when a single plant can, without any competition, occupy a large
enough area, moisture replacement by capillarity becomes
significant.


How Plants Obtain Water

Most gardeners know that plants acquire water and minerals through
their root systems, and leave it at that. But the process is not
quite that simple. The actively growing, tender root tips and almost
microscopic root hairs close to the tip absorb most of the plant's
moisture as they occupy new territory. As the root continues to
extend, parts behind the tip cease to be effective because, as soil
particles in direct contact with these tips and hairs dry out, the
older roots thicken and develop a bark, while most of the absorbent
hairs slough off. This rotation from being actively foraging tissue
to becoming more passive conductive and supportive tissue is
probably a survival adaptation, because the slow capillary movement
of soil moisture fails to replace what the plant used as fast as the
plant might like. The plant is far better off to aggressively seek
new water in unoccupied soil than to wait for the soil its roots
already occupy to be recharged.

A simple bit of old research magnificently illustrated the
significance of this. A scientist named Dittmer observed in 1937
that a single potted ryegrass plant allocated only 1 cubic foot of
soil to grow in made about 3 miles of new roots and root hairs every
day. (Ryegrasses are known to make more roots than most plants.) I
calculate that a cubic foot of silty soil offers about 30,000 square
feet of surface area to plant roots. If 3 miles of microscopic root
tips and hairs (roughly 16,000 lineal feet) draws water only from a
few millimeters of surrounding soil, then that single rye plant
should be able to continue ramifying into a cubic foot of silty soil
and find enough water for quite a few days before wilting. These
arithmetical estimates agree with my observations in the garden, and
with my experiences raising transplants in pots.


Lowered Plant Density: The Key to Water-Wise Gardening

I always think my latest try at writing a near-perfect garden book
is quite a bit better than the last. _Growing Vegetables West of the
Cascades_, recommended somewhat wider spacings on raised beds than I
did in 1980 because I'd repeatedly noticed that once a leaf canopy
forms, plant growth slows markedly. Adding a little more fertilizer
helps after plants "bump," but still the rate of growth never equals
that of younger plants. For years I assumed crowded plants stopped
producing as much because competition developed for light. But now I
see that unseen competition for root room also slows them down. Even
if moisture is regularly recharged by irrigation, and although
nutrients are replaced, once a bit of earth has been occupied by the
roots of one plant it is not so readily available to the roots of
another. So allocating more elbow room allows vegetables to get
larger and yield longer and allows the gardener to reduce the
frequency of irrigations.

Though hot, baking sun and wind can desiccate the few inches of
surface soil, withdrawals of moisture from greater depths are made
by growing plants transpiring moisture through their leaf surfaces.
The amount of water a growing crop will transpire is determined
first by the nature of the species itself, then by the amount of
leaf exposed to sun, air temperature, humidity, and wind. In these
respects, the crop is like an automobile radiator. With cars, the
more metal surfaces, the colder the ambient air, and the higher the
wind speed, the better the radiator can cool; in the garden, the
more leaf surfaces, the faster, warmer, and drier the wind, and the
brighter the sunlight, the more water is lost through transpiration.


Dealing with a Surprise Water Shortage

Suppose you are growing a conventional, irrigated garden and
something unanticipated interrupts your ability to water. Perhaps
you are homesteading and your well begins to dry up. Perhaps you're
a backyard gardener and the municipality temporarily restricts
usage. What to do?

First, if at all possible before the restrictions take effect, water
very heavily and long to ensure there is maximum subsoil moisture.
Then eliminate all newly started interplantings and ruthlessly hoe
out at least 75 percent of the remaining immature plants and about
half of those about two weeks away from harvest.

For example, suppose you've got a a 4-foot-wide intensive bed
holding seven rows of broccoli on 12 inch centers, or about 21
plants. Remove at least every other row and every other plant in the
three or four remaining rows. Try to bring plant density down to
those described in Chapter 5, "How to Grow It: A-Z"

Then shallowly hoe the soil every day or two to encourage the
surface inches to dry out and form a dust mulch. You water-wise
person--you're already dry gardening--now start fertigating.

How long available soil water will sustain a crop is determined by
how many plants are drawing on the reserve, how extensively their
root systems develop, and how many leaves are transpiring the
moisture. If there are no plants, most of the water will stay unused
in the barren soil through the entire growing season. If a crop
canopy is established midway through the growing season, the rate of
water loss will approximate that listed in the table in Chapter 1
"Estimated Irrigation Requirement." If by very close planting the
crop canopy is established as early as possible and maintained by
successive interplantings, as is recommended by most advocates of
raised-bed gardening, water losses will greatly exceed this rate.

Many vegetable species become mildly stressed when soil moisture has
dropped about half the way from capacity to the wilting point. On
very closely planted beds a crop can get in serious trouble without
irrigation in a matter of days. But if that same crop were planted
less densely, it might grow a few weeks without irrigation. And if
that crop were planted even farther apart so that no crop canopy
ever developed and a considerable amount of bare, dry earth were
showing, this apparent waste of growing space would result in an
even slower rate of soil moisture depletion. On deep, open soil the
crop might yield a respectable amount without needing any irrigation
at all.

West of the Cascades we expect a rainless summer; the surprise comes
that rare rainy year when the soil stays moist and we gather
bucketfuls of chanterelle mushrooms in early October. Though the
majority of maritime Northwest gardeners do not enjoy deep, open,
moisture-retentive soils, all except those with the shallowest soil
can increase their use of the free moisture nature provides and
lengthen the time between irrigations. The next chapter discusses
making the most of whatever soil depth you have. Most of our
region's gardens can yield abundantly without any rain at all if
only we reduce competition for available soil moisture, judiciously
fertigate some vegetable species, and practice a few other
water-wise tricks.

_Would lowering plant density as much as this book suggests equally
lower the yield of the plot? Surprisingly, the amount harvested does
not drop proportionately. In most cases having a plant density
one-eighth of that recommended by intensive gardening advocates will
result in a yield about half as great as on closely planted raised
beds._

Internet Readers: In the print copy of this book are color pictures
of my own "irrigationless" garden. Looking at them about here in the
book would add reality to these ideas.




Chapter 3

Helping Plants to Need Less Irrigation


Dry though the maritime Northwest summer is, we enter the growing
season with our full depth of soil at field capacity. Except on
clayey soils in extraordinarily frosty, high-elevation locations, we
usually can till and plant before the soil has had a chance to lose
much moisture.

There are a number of things we can do to make soil moisture more
available to our summer vegetables. The most obvious step is
thorough weeding. Next, we can keep the surface fluffed up with a
rotary tiller or hoe during April and May, to break its capillary
connection with deeper soil and accelerate the formation of a dry
dust mulch. Usually, weeding forces us to do this anyway. Also, if
it should rain during summer, we can hoe or rotary till a day or two
later and again help a new dust mulch to develop.


Building Bigger Root Systems

Without irrigation, most of the plant's water supply is obtained by
expansion into new earth that hasn't been desiccated by other
competing roots. Eliminating any obstacles to rapid growth of root
systems is the key to success. So, keep in mind a few facts about
how roots grow and prosper.

The air supply in soil limits or allows root growth. Unlike the
leaves, roots do not perform photosynthesis, breaking down carbon
dioxide gas into atmospheric oxygen and carbon. Yet root cells must
breathe oxygen. This is obtained from the air held in spaces between
soil particles. Many other soil-dwelling life forms from bacteria to
moles compete for this same oxygen. Consequently, soil oxygen levels
are lower than in the atmosphere. A slow exchange of gases does
occur between soil air and free atmosphere, but deeper in the soil
there will inevitably be less oxygen. Different plant species have
varying degrees of root tolerance for lack of oxygen, but they all
stop growing at some depth. Moisture reserves below the roots'
maximum depth become relatively inaccessible.

Soil compaction reduces the overall supply and exchange of soil air.
Compacted soil also acts as a mechanical barrier to root system
expansion. When gardening with unlimited irrigation or where rain
falls frequently, it is quite possible to have satisfactory growth
when only the surface 6 or 7 inches of soil facilitates root
development. When gardening with limited water, China's the limit,
because if soil conditions permit, many vegetable species are
capable of reaching 4, 5, and 8 eight feet down to find moisture and
nutrition.


Evaluating Potential Rooting Ability

One of the most instructive things a water-wise gardener can do is
to rent or borrow a hand-operated fence post auger and bore a
3-foot-deep hole. It can be even more educational to buy a short
section of ordinary water pipe to extend the auger's reach another 2
or 3 feet down. In soil free of stones, using an auger is more
instructive than using a conventional posthole digger or shoveling
out a small pit, because where soil is loose, the hole deepens
rapidly. Where any layer is even slightly compacted, one turns and
turns the bit without much effect. Augers also lift the materials
more or less as they are stratified. If your soil is somewhat stony
(like much upland soil north of Centralia left by the Vashon
Glacier), the more usual fence-post digger or common shovel works
better.

If you find more than 4 feet of soil, the site holds a dry-gardening
potential that increases with the additional depth. Some soils along
the floodplains of rivers or in broad valleys like the Willamette or
Skagit can be over 20 feet deep, and hold far more water than the
deepest roots could draw or capillary flow could raise during an
entire growing season. Gently sloping land can often carry 5 to 7
feet of open, usable soil. However, soils on steep hillsides become
increasingly thin and fragile with increasing slope.

Whether an urban, suburban, or rural gardener, you should make no
assumptions about the depth and openness of the soil at your
disposal. Dig a test hole. If you find less than 2 unfortunate feet
of open earth before hitting an impermeable obstacle such as rock or
gravel, not much water storage can occur and the only use this book
will hold for you is to guide your move to a more likely gardening
location or encourage the house hunter to seek further. Of course,
you can still garden quite successfully on thin soil in the
conventional, irrigated manner. _Growing Vegetables West of the
Cascades_ will be an excellent guide for this type of situation.


Eliminating Plowpan

Deep though the soil may be, any restriction of root expansion
greatly limits the ability of plants to aggressively find water. A
compacted subsoil or even a thin compressed layer such as plowpan
may function as such a barrier. Though moisture will still rise
slowly by capillarity and recharge soil above plowpan, plants obtain
much more water by rooting into unoccupied, damp soil. Soils close
to rivers or on floodplains may appear loose and infinitely deep but
may hide subsoil streaks of droughty gravel that effectively stops
root growth. Some of these conditions are correctable and some are
not.

Plowpan is very commonly encountered by homesteaders on farm soils
and may be found in suburbia too, but fortunately it is the easiest
obstacle to remedy. Traditionally, American croplands have been
tilled with the moldboard plow. As this implement first cuts and
then flips a 6-or 7-inch-deep slice of soil over, the sole--the part
supporting the plow's weight--presses heavily on the earth about 7
inches below the surface. With each subsequent plowing the plow sole
rides at the same 7-inch depth and an even more compacted layer
develops. Once formed plowpan prevents the crop from rooting into
the subsoil. Since winter rains leach nutrients from the topsoil and
deposit them in the subsoil, plowpan prevents access to these
nutrients and effectively impoverishes the field. So wise farmers
periodically use a subsoil plow to fracture the pan.

Plowpan can seem as firm as a rammed-earth house; once established,
it can last a long, long time. My own garden land is part of what
was once an old wheat farm, one of the first homesteads of the
Oregon Territory. From about 1860 through the 1930s, the field
produced small grains. After wheat became unprofitable, probably
because of changing market conditions and soil exhaustion, the field
became an unplowed pasture. Then in the 1970s it grew daffodil
bulbs, occasioning more plowing. All through the '80s my soil again
rested under grass. In 1987, when I began using the land, there was
still a 2-inch-thick, very hard layer starting about 7 inches down.
Below 9 inches the open earth is soft as butter as far as I've ever
dug.

On a garden-sized plot, plowpan or compacted subsoil is easily
opened with a spading fork or a very sharp common shovel. After
normal rotary tilling, either tool can fairly easily be wiggled 12
inches into the earth and small bites of plowpan loosened. Once this
laborious chore is accomplished the first time, deep tillage will be
far easier. In fact, it becomes so easy that I've been looking for a
custom-made fork with longer tines.


Curing Clayey Soils

In humid climates like ours, sandy soils may seem very open and
friable on the surface but frequently hold some unpleasant subsoil
surprises. Over geologic time spans, mineral grains are slowly
destroyed by weak soil acids and clay is formed from the breakdown
products. Then heavy winter rainfall transports these minuscule clay
particles deeper into the earth, where they concentrate. It is not
unusual to find a sandy topsoil underlaid with a dense, cement-like,
clayey sand subsoil extending down several feet. If very impervious,
a thick, dense deposition like this may be called hardpan.

The spading fork cannot cure this condition as simply as it can
eliminate thin plowpan. Here is one situation where, if I had a
neighbor with a large tractor and subsoil plow, I'd hire him to
fracture my land 3 or 4 feet deep. Painstakingly double or even
triple digging will also loosen this layer. Another possible
strategy for a smaller garden would be to rent a gasoline-powered
posthole auger, spread manure or compost an inch or two thick, and
then bore numerous, almost adjoining holes 4 feet deep all over the
garden.

Clayey subsoil can supply surprisingly larger amounts of moisture
than the granular sandy surface might imply, but only if the earth
is opened deeply and becomes more accessible to root growth.
Fortunately, once root development increases at greater depths, the
organic matter content and accessibility of this clayey layer can be
maintained through intelligent green manuring, postponing for years
the need to subsoil again. Green manuring is discussed in detail
shortly.

Other sites may have gooey, very fine clay topsoils, almost
inevitably with gooey, very fine clay subsoils as well. Though
incorporation of extraordinarily large quantities of organic matter
can turn the top few inches into something that behaves a little
like loam, it is quite impractical to work in humus to a depth of 4
or 5 feet. Root development will still be limited to the surface
layer. Very fine clays don't make likely dry gardens.

Not all clay soils are "fine clay soils," totally compacted and
airless. For example, on the gentler slopes of the geologic old
Cascades, those 50-million-year-old black basalts that form the
Cascades foothills and appear in other places throughout the
maritime Northwest, a deep, friable, red clay soil called (in
Oregon) Jori often forms. Jori clays can be 6 to 8 feet deep and are
sufficiently porous and well drained to have been used for highly
productive orchard crops. Water-wise gardeners can do wonders with
Joris and other similar soils, though clays never grow the best root
crops.


Spotting a Likely Site

Observing the condition of wild plants can reveal a good site to
garden without much irrigation. Where Himalaya or Evergreen
blackberries grow 2 feet tall and produce small, dull-tasting fruit,
there is not much available soil moisture. Where they grow 6 feet
tall and the berries are sweet and good sized, there is deep, open
soil. When the berry vines are 8 or more feet tall and the fruits
are especially huge, usually there is both deep, loose soil and a
higher than usual amount of fertility.

Other native vegetation can also reveal a lot about soil moisture
reserves. For years I wondered at the short leaders and sad
appearance of Douglas fir in the vicinity of Yelm, Washington. Were
they due to extreme soil infertility? Then I learned that conifer
trees respond more to summertime soil moisture than to fertility. I
obtained a soil survey of Thurston County and discovered that much
of that area was very sandy with gravelly subsoil. Eureka!

The Soil Conservation Service (SCS), a U.S. Government agency, has
probably put a soil auger into your very land or a plot close by.
Its tests have been correlated and mapped; the soils underlying the
maritime Northwest have been named and categorized by texture,
depth, and ability to provide available moisture. The maps are
precise and detailed enough to approximately locate a city or
suburban lot. In 1987, when I was in the market for a new homestead,
I first went to my county SCS office, mapped out locations where the
soil was suitable, and then went hunting. Most counties have their
own office.


Using Humus to Increase Soil Moisture

Maintaining topsoil humus content in the 4 to 5 percent range is
vital to plant health, vital to growing more nutritious food, and
essential to bringing the soil into that state of easy workability
and cooperation known as good tilth. Humus is a spongy substance
capable of holding several times more available moisture than clay.
There are also new synthetic, long-lasting soil amendments that hold
and release even more moisture than humus. Garden books frequently
recommend tilling in extraordinarily large amounts of organic matter
to increase a soil's water-holding capacity in the top few inches.

Humus can improve many aspects of soil but will not reduce a
garden's overall need for irrigation, because it is simply not
practical to maintain sufficient humus deeply enough. Rotary tilling
only blends amendments into the top 6 or 7 inches of soil. Rigorous
double digging by actually trenching out 12 inches and then spading
up the next foot theoretically allows one to mix in significant
amounts of organic matter to nearly 24 inches. But plants can use
water from far deeper than that. Let's realistically consider how
much soil moisture reserves might be increased by double digging and
incorporating large quantities of organic matter.

A healthy topsoil organic matter level in our climate is about 4
percent. This rapidly declines to less than 0.5 percent in the
subsoil. Suppose inches-thick layers of compost were spread and, by
double digging, the organic matter content of a very sandy soil were
amended to 10 percent down to 2 feet. If that soil contained little
clay, its water-holding ability in the top 2 feet could be doubled.
Referring to the chart "Available Moisture" in Chapter 2, we see
that sandy soil can release up to 1 inch of water per foot. By dint
of massive amendment we might add 1 inch of available moisture per
foot of soil to the reserve. That's 2 extra inches of water, enough
to increase the time an ordinary garden can last between heavy
irrigations by a week or 10 days.

If the soil in question were a silty clay, it would naturally make 2
1/2 inches available per foot. A massive humus amendment would
increase that to 3 1/2 inches in the top foot or two, relatively not
as much benefit as in sandy soil. And I seriously doubt that many
gardeners would be willing to thoroughly double dig to an honest 24
inches.

Trying to maintain organic matter levels above 10 percent is an
almost self-defeating process. The higher the humus level gets, the
more rapidly organic matter tends to decay. Finding or making enough
well-finished compost to cover the garden several inches deep (what
it takes to lift humus levels to 10 percent) is enough of a job.
Double digging just as much more into the second foot is even more
effort. But having to repeat that chore every year or two becomes
downright discouraging. No, either your soil naturally holds enough
moisture to permit dry gardening, or it doesn't.


Keeping the Subsoil Open with Green Manuring

When roots decay, fresh organic matter and large, long-lasting
passageways can be left deep in the soil, allowing easier air
movement and facilitating entry of other roots. But no cover crop
that I am aware of will effectively penetrate firm plowpan or other
resistant physical obstacles. Such a barrier forces all plants to
root almost exclusively in the topsoil. However, once the subsoil
has been mechanically fractured the first time, and if recompaction
is avoided by shunning heavy tractors and other machinery, green
manure crops can maintain the openness of the subsoil.

To accomplish this, correct green manure species selection is
essential. Lawn grasses tend to be shallow rooting, while most
regionally adapted pasture grasses can reach down about 3 feet at
best. However, orchard grass (called coltsfoot in English farming
books) will grow down 4 or more feet while leaving a massive amount
of decaying organic matter in the subsoil after the sod is tilled
in. Sweet clover, a biennial legume that sprouts one spring then
winters over to bloom the next summer, may go down 8 feet. Red
clover, a perennial species, may thickly invade the top 5 feet.
Other useful subsoil busters include densely sown Umbelliferae such
as carrots, parsley, and parsnip. The chicory family also makes very
large and penetrating taproots.

Though seed for wild chicory is hard to obtain, cheap varieties of
endive (a semicivilized relative) are easily available. And several
pounds of your own excellent parsley or parsnip seed can be easily
produced by letting about 10 row feet of overwintering roots form
seed. Orchard grass and red clover can be had quite inexpensively at
many farm supply stores. Sweet clover is not currently grown by our
region's farmers and so can only be found by mail from Johnny's
Selected Seeds (see Chapter 5 for their address). Poppy seed used
for cooking will often sprout. Sown densely in October, it forms a
thick carpet of frilly spring greens underlaid with countless
massive taproots that decompose very rapidly if the plants are
tilled in in April before flower stalks begin to appear. Beware if
using poppies as a green manure crop: be sure to till them in early
to avoid trouble with the DEA or other authorities.

For country gardeners, the best rotations include several years of
perennial grass-legume-herb mixtures to maintain the openness of the
subsoil followed by a few years of vegetables and then back (see
Newman Turner's book in more reading). I plan my own garden this
way. In October, after a few inches of rain has softened the earth,
I spread 50 pounds of agricultural lime per 1,000 square feet and
break the thick pasture sod covering next year's garden plot by
shallow rotary tilling. Early the next spring I broadcast a
concoction I call "complete organic fertilizer" (see _Growing
Vegetables West of the Cascades_ or the _Territorial Seed Company
Catalog_), till again after the soil dries down a bit, and then use
a spading fork to open the subsoil before making a seedbed. The
first time around, I had to break the century-old plowpan--forking
compacted earth a foot deep is a lot of work. In subsequent
rotations it is much much easier.

For a couple of years, vegetables will grow vigorously on this new
ground supported only with a complete organic fertilizer. But
vegetable gardening makes humus levels decline rapidly. So every few
years I start a new garden on another plot and replant the old
garden to green manures. I never remove vegetation during the long
rebuilding under green manures, but merely mow it once or twice a
year and allow the organic matter content of the soil to redevelop.
If there ever were a place where chemical fertilizers might be
appropriate around a garden, it would be to affordably enhance the
growth of biomass during green manuring.

Were I a serious city vegetable gardener, I'd consider growing
vegetables in the front yard for a few years and then switching to
the back yard. Having lots of space, as I do now, I keep three or
four garden plots available, one in vegetables and the others
restoring their organic matter content under grass.


Mulching

Gardening under a permanent thick mulch of crude organic matter is
recommended by Ruth Stout (see the listing for her book in More
Reading) and her disciples as a surefire way to drought-proof
gardens while eliminating virtually any need for tillage, weeding,
and fertilizing. I have attempted the method in both Southern
California and western Oregon--with disastrous results in both
locations. What follows in this section is addressed to gardeners
who have already read glowing reports about mulching.

Permanent mulching with vegetation actually does not reduce
summertime moisture loss any better than mulching with dry soil,
sometimes called "dust mulching." True, while the surface layer
stays moist, water will steadily be wicked up by capillarity and be
evaporated from the soil's surface. If frequent light sprinkling
keeps the surface perpetually moist, subsoil moisture loss can occur
all summer, so unmulched soil could eventually become desiccated
many feet deep. However, capillary movement only happens when soil
is damp. Once even a thin layer of soil has become quite dry it
almost completely prevents any further movement. West of the
Cascades, this happens all by itself in late spring. One hot, sunny
day follows another, and soon the earth's surface seems parched.

Unfortunately, by the time a dusty layer forms, quite a bit of soil
water may have risen from the depths and been lost. The gardener can
significantly reduce spring moisture loss by frequently hoeing weeds
until the top inch or two of earth is dry and powdery. This effort
will probably be necessary in any case, because weeds will germinate
prolifically until the surface layer is sufficiently desiccated. On
the off chance it should rain hard during summer, it is very wise to
again hoe a few times to rapidly restore the dust mulch. If hand
cultivation seems very hard work, I suggest you learn to sharpen
your hoe.

A mulch of dry hay, grass clippings, leaves, and the like will also
retard rapid surface evaporation. Gardeners think mulching prevents
moisture loss better than bare earth because under mulch the soil
stays damp right to the surface. However, dig down 4 to 6 inches
under a dust mulch and the earth is just as damp as under hay. And,
soil moisture studies have proved that overall moisture loss using
vegetation mulch slightly exceeds loss under a dust mulch.

West of the Cascades, the question of which method is superior is a
bit complex, with pros and cons on both sides. Without a long winter
freeze to set populations back, permanent thick mulch quickly breeds
so many slugs, earwhigs, and sowbugs that it cannot be maintained
for more than one year before vegetable gardening becomes very
difficult. Laying down a fairly thin mulch in June after the soil
has warmed up well, raking up what remains of the mulch early the
next spring, and composting it prevents destructive insect
population levels from developing while simultaneously reducing
surface compaction by winter rains and beneficially enhancing the
survival and multiplication of earthworms. But a thin mulch also
enhances the summer germination of weed seeds without being thick
enough to suppress their emergence. And any mulch, even a thin one,
makes hoeing virtually impossible, while hand weeding through mulch
is tedious.

Mulch has some unqualified pluses in hotter climates. Most of the
organic matter in soil and consequently most of the available
nitrogen is found in the surface few inches. Levels of other mineral
nutrients are usually two or three times as high in the topsoil as
well. However, if the surface few inches of soil becomes completely
desiccated, no root activity will occur there and the plants are
forced to feed deeper, in soil far less fertile. Keeping the topsoil
damp does greatly improve the growth of some shallow-feeding species
such as lettuce and radishes. But with our climate's cool nights,
most vegetables need the soil as warm as possible, and the cooling
effect of mulch can be as much a hindrance as a help. I've tried
mulching quite a few species while dry gardening and found little or
no improvement in plant growth with most of them. Probably, the
enhancement of nutrition compensates for the harm from lowering soil
temperature. Fertigation is better all around.


Windbreaks

Plants transpire more moisture when the sun shines, when
temperatures are high, and when the wind blows; it is just like
drying laundry. Windbreaks also help the garden grow in winter by
increasing temperature. Many other garden books discuss windbreaks,
and I conclude that I have a better use for the small amount of
words my publisher allows me than to repeat this data; Binda
Colebrook's [i]Winter Gardening in the Maritime Northwest[i]
(Sasquatch Books, 1989) is especially good on this topic.


Fertilizing, Fertigating and Foliar Spraying

In our heavily leached region almost no soil is naturally rich,
while fertilizers, manures, and potent composts mainly improve the
topsoil. But the water-wise gardener must get nutrition down deep,
where the soil stays damp through the summer.

If plants with enough remaining elbow room stop growing in summer
and begin to appear gnarly, it is just as likely due to lack of
nutrition as lack of water. Several things can be done to limit or
prevent midsummer stunting. First, before sowing or transplanting
large species like tomato, squash or big brassicas, dig out a small
pit about 12 inches deep and below that blend in a handful or two of
organic fertilizer. Then fill the hole back in. This double-digging
process places concentrated fertility mixed 18 to 24 inches below
the seeds or seedlings.

Foliar feeding is another water-wise technique that keeps plants
growing through the summer. Soluble nutrients sprayed on plant
leaves are rapidly taken into the vascular system. Unfortunately,
dilute nutrient solutions that won't burn leaves only provoke a
strong growth response for 3 to 5 days. Optimally, foliar nutrition
must be applied weekly or even more frequently. To efficiently spray
a garden larger than a few hundred square feet, I suggest buying an
industrial-grade, 3-gallon backpack sprayer with a side-handle pump.
Approximate cost as of this writing was $80. The store that sells it
(probably a farm supply store) will also support you with a complete
assortment of inexpensive nozzles that can vary the rate of emission
and the spray pattern. High-quality equipment like this outlasts
many, many cheaper and smaller sprayers designed for the consumer
market, and replacement parts are also available. Keep in mind that
consumer merchandise is designed to be consumed; stuff made for
farming is built to last.


Increasing Soil Fertility Saves Water

Does crop growth equal water use? Most people would say this
statement seems likely to be true.

Actually, faster-growing crops use much less soil moisture than
slower-growing ones. As early as 1882 it was determined that less
water is required to produce a pound of plant material when soil is
fertilized than when it is not fertilized. One experiment required
1,100 pounds of water to grow 1 pound of dry matter on infertile
soil, but only 575 pounds of water to produce a pound of dry matter
on rich land. Perhaps the single most important thing a water-wise
gardener can do is to increase the fertility of the soil, especially
the subsoil.

_Poor plant nutrition increases the water cost of every pound of dry
matter produced._

Using foliar fertilizers requires a little caution and forethought.
Spinach, beet, and chard leaves seem particularly sensitive to
foliars (and even to organic insecticides) and may be damaged by
even half-strength applications. And the cabbage family coats its
leaf surfaces with a waxy, moisture-retentive sealant that makes
sprays bead up and run off rather than stick and be absorbed. Mixing
foliar feed solutions with a little spreader/sticker, Safer's Soap,
or, if bugs are also a problem, with a liquid organic insecticide
like Red Arrow (a pyrethrum-rotenone mix), eliminates surface
tension and allows the fertilizer to have an effect on brassicas.

Sadly, in terms of nutrient balance, the poorest foliar sprays are
organic. That's because it is nearly impossible to get significant
quantities of phosphorus or calcium into solution using any
combination of fish emulsion and seaweed or liquid kelp. The most
useful possible organic foliar is 1/2 to 1 tablespoon each of fish
emulsion and liquid seaweed concentrate per gallon of water.

Foliar spraying and fertigation are two occasions when I am
comfortable supplementing my organic fertilizers with water-soluble
chemical fertilizers. The best and most expensive brand is
Rapid-Gro. Less costly concoctions such as Peters 20-20-20 or the
other "Grows," don't provide as complete trace mineral support or
use as many sources of nutrition. One thing fertilizer makers find
expensive to accomplish is concocting a mixture of soluble nutrients
that also contains calcium, a vital plant food. If you dissolve
calcium nitrate into a solution containing other soluble plant
nutrients, many of them will precipitate out because few calcium
compounds are soluble. Even Rapid-Gro doesn't attempt to supply
calcium. Recently I've discovered better-quality hydroponic nutrient
solutions that do use chemicals that provide soluble calcium. These
also make excellent foliar sprays. Brands of hydroponic nutrient
solutions seem to appear and vanish rapidly. I've had great luck
with Dyna-Gro 7-9-5. All these chemicals are mixed at about 1
tablespoon per gallon.


Vegetables That:

Like foliars

  Asparagus Carrots Melons Squash
  Beans Cauliflower Peas Tomatoes
  Broccoli Brussels sprouts Cucumbers
  Cabbage Eggplant Radishes
  Kale Rutabagas Potatoes

Don't like foliars

  Beets Leeks Onions Spinach
  Chard Lettuce Peppers

Like fertigation

  Brussels sprouts Kale Savoy cabbage
  Cucumbers Melons Squash
  Eggplant Peppers Tomatoes


Fertigation every two to four weeks is the best technique for
maximizing yield while minimizing water use. I usually make my first
fertigation late in June and continue periodically through early
September. I use six or seven plastic 5-gallon "drip system"
buckets, (see below) set one by each plant, and fill them all with a
hose each time I work in the garden. Doing 12 or 14 plants each time
I'm in the garden, it takes no special effort to rotate through them
all more or less every three weeks.

To make a drip bucket, drill a 3/16-inch hole through the side of a
4-to-6-gallon plastic bucket about 1/4-inch up from the bottom, or
in the bottom at the edge. The empty bucket is placed so that the
fertilized water drains out close to the stem of a plant. It is then
filled with liquid fertilizer solution. It takes 5 to 10 minutes for
5 gallons to pass through a small opening, and because of the slow
flow rate, water penetrates deeply into the subsoil without wetting
much of the surface. Each fertigation makes the plant grow very
rapidly for two to three weeks, more I suspect as a result of
improved nutrition than from added moisture. Exactly how and when to
fertigate each species is explained in Chapter 5.

Organic gardeners may fertigate with combinations of fish emulsion
and seaweed at the same dilution used for foliar spraying, or with
compost/manure tea. Determining the correct strength to make compost
tea is a matter of trial and error. I usually rely on weak Rapid-Gro
mixed at half the recommended dilution. The strength of the
fertilizer you need depends on how much and deeply you placed
nutrition in the subsoil.




Chapter 4

Water-Wise Gardening Year-Round


Early Spring: The Easiest Unwatered Garden

West of the Cascades, most crops started in February and March
require no special handling when irrigation is scarce. These include
peas, early lettuce, radishes, kohlrabi, early broccoli, and so
forth. However, some of these vegetables are harvested as late as
June, so to reduce their need for irrigation, space them wider than
usual. Spring vegetables also will exhaust most of the moisture from
the soil before maturing, making succession planting impossible
without first irrigating heavily. Early spring plantings are best
allocated one of two places in the garden plan: either in that part
of the garden that will be fully irrigated all summer or in a part
of a big garden that can affordably remain bare during the summer
and be used in October for receiving transplants of overwintering
crops. The garden plan and discussion in Chapter 6 illustrate these
ideas in detail.


Later in Spring: Sprouting Seeds Without Watering

For the first years that I experimented with dry gardening I went
overboard and attempted to grow food as though I had no running
water at all. The greatest difficulty caused by this self-imposed
handicap was sowing small-seeded species after the season warmed up.

Sprouting what we in the seed business call "big seed"--corn, beans,
peas, squash, cucumber, and melon--is relatively easy without
irrigation because these crops are planted deeply, where soil
moisture still resides long after the surface has dried out. And
even if it is so late in the season that the surface has become very
dry, a wide, shallow ditch made with a shovel will expose moist soil
several inches down. A furrow can be cut in the bottom of that damp
"valley" and big seeds germinated with little or no watering.

Tillage breaks capillary connections until the fluffy soil
resettles. This interruption is useful for preventing moisture loss
in summer, but the same phenomenon makes the surface dry out in a
flash. In recently tilled earth, successfully sprouting small seeds
in warm weather is dicey without frequent watering.

With a bit of forethought, the water-wise gardener can easily
reestablish capillarity below sprouting seeds so that moisture held
deeper in the soil rises to replace that lost from surface layers,
reducing or eliminating the need for watering. The principle here
can be easily demonstrated. In fact, there probably isn't any
gardener who has not seen the phenomenon at work without realizing
it. Every gardener has tilled the soil, gone out the next morning,
and noticed that his or her compacted footprints were moist while
the rest of the earth was dry and fluffy. Foot pressure restored
capillarity, and during the night, fresh moisture replaced what had
evaporated.

This simple technique helps start everything except carrots and
parsnips (which must have completely loose soil to develop
correctly). All the gardener must do is intentionally compress the
soil below the seeds and then cover the seeds with a mulch of loose,
dry soil. Sprouting seeds then rest atop damp soil exactly they lie
on a damp blotter in a germination laboratory's covered petri dish.
This dampness will not disappear before the sprouting seedling has
propelled a root several inches farther down and is putting a leaf
into the sunlight.

I've used several techniques to reestablish capillarity after
tilling. There's a wise old plastic push planter in my garage that
first compacts the tilled earth with its front wheel, cuts a furrow,
drops the seed, and then with its drag chain pulls loose soil over
the furrow. I've also pulled one wheel of a garden cart or pushed a
lightly loaded wheelbarrow down the row to press down a wheel track,
sprinkled seed on that compacted furrow, and then pulled loose soil
over it.


Handmade Footprints

Sometimes I sow large brassicas and cucurbits in clumps above a
fertilized, double-dug spot. First, in a space about 18 inches
square, I deeply dig in complete organic fertilizer. Then with my
fist I punch down a depression in the center of the fluffed-up
mound. Sometimes my fist goes in so easily that I have to replace a
little more soil and punch it down some more. The purpose is not to
make rammed earth or cement, but only to reestablish capillarity by
having firm soil under a shallow, fist-sized depression. Then a
pinch of seed is sprinkled atop this depression and covered with
fine earth. Even if several hot sunny days follow I get good
germination without watering. This same technique works excellently
on hills of squash, melon and cucumber as well, though these
large-seeded species must be planted quite a bit deeper.


Summer: How to Fluid Drill Seeds

Soaking seeds before sowing is another water-wise technique,
especially useful later in the season. At bedtime, place the seeds
in a half-pint mason jar, cover with a square of plastic window
screen held on with a strong rubber band, soak the seeds overnight,
and then drain them first thing in the morning. Gently rinse the
seeds with cool water two or three times daily until the root tips
begin to emerge. As soon as this sign appears, the seed must be
sown, because the newly emerging roots become increasingly subject
to breaking off as they develop and soon form tangled masses.
Presprouted seeds may be gently blended into some crumbly, moist
soil and this mixture gently sprinkled into a furrow and covered. If
the sprouts are particularly delicate or, as with carrots, you want
a very uniform stand, disperse the seeds in a starch gelatin and
imitate what commercial vegetable growers call fluid drilling.

Heat one pint of water to the boiling point. Dissolve in 2 to 3
tablespoons of ordinary cornstarch. Place the mixture in the
refrigerator to cool. Soon the liquid will become a soupy gel.
Gently mix this cool starch gel with the sprouting seeds, making
sure the seeds are uniformly blended. Pour the mixture into a
1-quart plastic zipper bag and, scissors in hand, go out to the
garden. After a furrow--with capillarity restored--has been
prepared, cut a small hole in one lower corner of the plastic bag.
The hole size should be under 1/4 inch in diameter. Walk quickly
down the row, dribbling a mixture of gel and seeds into the furrow.
Then cover. You may have to experiment a few times with cooled gel
minus seeds until you divine the proper hole size, walking speed and
amount of gel needed per length of furrow. Not only will presprouted
seeds come up days sooner, and not only will the root be penetrating
moist soil long before the shoot emerges, but the stand of seedlings
will be very uniformly spaced and easier to thin. After fluid
drilling a few times you'll realize that one needs quite a bit less
seed per length of row than you previously thought.


Establishing the Fall and Winter Garden

West of the Cascades, germinating fall and winter crops in the heat
of summer is always difficult. Even when the entire garden is well
watered, midsummer sowings require daily attention and frequent
sprinkling; however, once they have germinated, keeping little
seedlings growing in an irrigated garden usually requires no more
water than the rest of the garden gets. But once hot weather comes,
establishing small seeds in the dry garden seems next to impossible
without regular watering. Should a lucky, perfectly timed, and
unusually heavy summer rainfall sprout your seeds, they still would
not grow well because the next few inches of soil would at best be
only slightly moist.

A related problem many backyard gardeners have with establishing the
winter and overwintered garden is finding enough space for both the
summer and winter crops. The nursery bed solves both these problems.
Instead of trying to irrigate the entire area that will eventually
be occupied by a winter or overwintered crop at maturity, the
seedlings are first grown in irrigated nurseries for transplanting
in autumn after the rains come back. Were I desperately short of
water I'd locate my nursery where it got only morning sun and sow a
week or 10 days earlier to compensate for the slower growth.


  Vegetables to Start in a Nursery Bed

  Variety               Sowing date         Transplanting date

  Fall/winter lettuce   mid-August          early October
  Leeks                 early April         July
  Overwintered onions   early-mid August    December/January
  Spring cabbage        mid-late August     November/December
  Spring cauliflower    mid-August          October/November 1st
  Winter scallions      mid-July            mid-October


Seedlings in pots and trays are hard to keep moist and require daily
tending. Fortunately, growing transplants in little pots is not
necessary because in autumn, when they'll be set out, humidity is
high, temperatures are cool, the sun is weak, and transpiration
losses are minimal, so seedling transplants will tolerate
considerable root loss. My nursery is sown in rows about 8 inches
apart across a raised bed and thinned gradually to prevent crowding,
because crowded seedlings are hard to dig out without damage. When
the prediction of a few days of cloudy weather encourages
transplanting, the seedlings are lifted with a large, sharp knife.
If the fall rains are late and/or the crowded seedlings are getting
leggy, a relatively small amount of irrigation will moisten the
planting areas. Another light watering at transplanting time will
almost certainly establish the seedlings quite successfully. And,
finding room for these crops ceases to be a problem because fall
transplants can be set out as a succession crop following hot
weather vegetables such as squash, melons, cucumbers, tomatoes,
potatoes, and beans.

  Vegetables that must be heavily irrigated
  (These crops are not suitable for dry gardens.)

  Bulb Onions (for fall harvest)
  Celeriac
  Celery
  Chinese cabbage
  Lettuce (summer and fall)
  Radishes (summer and fall)
  Scallions (for summer harvest)
  Spinach (summer)




Chapter 5

How to Grow It with Less Irrigation: A-Z


First, a Word About Varieties

As recently as the 1930s, most American country folk still did not
have running water. With water being hand-pumped and carried in
buckets, and precious, their vegetable gardens had to be grown with
a minimum of irrigation. In the otherwise well-watered East, one
could routinely expect several consecutive weeks every summer
without rain. In some drought years a hot, rainless month or longer
could go by. So vegetable varieties were bred to grow through dry
spells without loss, and traditional American vegetable gardens were
designed to help them do so.

I began gardening in the early 1970s, just as the raised-bed method
was being popularized. The latest books and magazine articles all
agreed that raising vegetables in widely separated single rows was a
foolish imitation of commercial farming, that commercial vegetables
were arranged that way for ease of mechanical cultivation. Closely
planted raised beds requiring hand cultivation were alleged to be
far more productive and far more efficient users of irrigation
because water wasn't evaporating from bare soil.

I think this is more likely to be the truth: Old-fashioned gardens
used low plant densities to survive inevitable spells of
rainlessness. Looked at this way, widely separated vegetables in
widely separated rows may be considered the more efficient users of
water because they consume soil moisture that nature freely puts
there. Only after, and if, these reserves are significantly depleted
does the gardener have to irrigate. The end result is surprisingly
more abundant than a modern gardener educated on intensive,
raised-bed propaganda would think.

Finding varieties still adapted to water-wise gardening is becoming
difficult. Most American vegetables are now bred for
irrigation-dependent California. Like raised-bed gardeners,
vegetable farmers have discovered that they can make a bigger profit
by growing smaller, quick-maturing plants in high-density spacings.
Most modern vegetables have been bred to suit this method. Many new
varieties can't forage and have become smaller, more determinate,
and faster to mature. Actually, the larger, more sprawling heirloom
varieties of the past were not a great deal less productive overall,
but only a little later to begin yielding.

Fortunately, enough of the old sorts still exist that a selective
and varietally aware home gardener can make do. Since I've become
water-wiser, I'm interested in finding and conserving heirlooms that
once supported large numbers of healthy Americans in relative
self-sufficiency. My earlier book, being a guide to what passes for
ordinary vegetable gardening these days, assumed the availability of
plenty of water. The varieties I recommended in [i]Growing
Vegetables West of the Cascades[i] were largely modern ones, and the
seed companies I praised most highly focused on top-quality
commercial varieties. But, looking at gardening through the filter
of limited irrigation, other, less modern varieties are often far
better adapted and other seed companies sometimes more likely
sources.

Seed Company Directory*

Abundant Life See Foundation: P.O. Box 772, Port Townsend, WA 98368
_(ABL)_

Johnny's Selected Seeds: Foss Hill Road, Albion, Maine 04910 _(JSS)_

Peace Seeds: 2345 SE Thompson Street, Corvallis, OR 97333 _(PEA)_

Ronninger's Seed Potatoes: P.O. Box 1838, Orting, WA 98360 _(RSP)_

Stokes Seeds Inc. Box 548, Buffalo, NY 14240 _(STK)_

Territorial Seed Company: P.O. Box 20, Cottage Grove, OR 97424
_(TSC)_

*Throughout the growing directions that follow in this chapter, the
reader will be referred to a specific company only for varieties
that are not widely available.

I have again come to appreciate the older style of
vegetable--sprawling, large framed, later maturing, longer yielding,
vigorously rooting. However, many of these old-timers have not seen
the attentions of a professional plant breeder for many years and
throw a fair percentage of bizarre, misshapen, nonproductive plants.
These "off types" can be compensated for by growing a somewhat
larger garden and allowing for some waste. Dr. Alan Kapuler, who
runs Peace Seeds, has brilliantly pointed out to me why heirloom
varieties are likely to be more nutritious. Propagated by centuries
of isolated homesteaders, heirlooms that survived did so because
these superior varieties helped the gardeners' better-nourished
babies pass through the gauntlet of childhood illnesses.


Plant Spacing: The Key to Water-Wise Gardening

Reduced plant density is the essence of dry gardening. The
recommended spacings in this section are those I have found workable
at Elkton, Oregon. My dry garden is generally laid out in single
rows, the row centers 4 feet apart. Some larger crops, like
potatoes, tomatoes, beans, and cucurbits (squash, cucumbers, and
melons) are allocated more elbow room. Those few requiring intensive
irrigation are grown on a raised bed, tightly spaced. I cannot
prescribe what would be the perfect, most efficient spacing for your
garden. Are your temperatures lower than mine and evaporation less?
Or is your weather hotter? Does your soil hold more, than less than,
or just as much available moisture as mine? Is it as deep and open
and moisture retentive?

To help you compare your site with mine, I give you the following
data. My homestead is only 25 miles inland and is always several
degrees cooler in summer than the Willamette Valley. Washingtonians
and British Columbians have cooler days and a greater likelihood of
significant summertime rain and so may plant a little closer
together. Inland gardeners farther south or in the Willamette Valley
may want to spread their plants out a little farther.

Living on 16 acres, I have virtually unlimited space to garden in.
The focus of my recent research has been to eliminate irrigation as
much as possible while maintaining food quality. Those with thinner
soil who are going to depend more on fertigation may plant closer,
how close depending on the amount of water available. More
irrigation will also give higher per-square-foot yields.

_Whatever your combination of conditions, your results can only be
determined by trial._ I'd suggest you become water-wise by testing a
range of spacings.


When to Plant

If you've already been growing an irrigated year-round garden, this
book's suggested planting dates may surprise you. And as with
spacing, sowing dates must also be wisely adjusted to your location.
The planting dates in this chapter are what I follow in my own
garden. It is impractical to include specific dates for all the
microclimatic areas of the maritime Northwest and for every
vegetable species. Readers are asked to make adjustments by
understanding their weather relative to mine.

Gardeners to the north of me and at higher elevations should make
their spring sowings a week or two later than the dates I use. In
the Garden Valley of Roseburg and south along I-5, start spring
plantings a week or two earlier. Along the southern Oregon coast and
in northern California, start three or four weeks sooner than I do.

Fall comes earlier to the north of me and to higher-elevation
gardens; end-of-season growth rates there also slow more profoundly
than they do at Elkton. Summers are cooler along the coast; that has
the same effect of slowing late-summer growth. Items started after
midsummer should be given one or two extra growing weeks by coastal,
high-elevation, and northern gardeners. Gardeners to the south
should sow their late crops a week or two later than I do; along the
south Oregon coast and in northern California, two to four weeks
later than I do.


Arugula (Rocket)

The tender, peppery little leaves make winter salads much more
interesting.

_Sowing date:_ I delay sowing until late August or early September
so my crowded patch of arugula lasts all winter and doesn't make
seed until March. Pregerminated seeds emerge fast and strong.
Sprouted in early October, arugula still may reach eating size in
midwinter.

_Spacing:_ Thinly seed a row into any vacant niche. The seedlings
will be insignificantly small until late summer.

_Irrigation:_ If the seedlings suffer a bit from moisture stress
they'll catch up rapidly when the fall rains begin.

_Varieties:_ None.


Beans of All Sorts

Heirloom pole beans once climbed over considerable competition while
vigorously struggling for water, nutrition, and light. Modern bush
varieties tend to have puny root systems.

_Sowing date:_ Mid-April is the usual time on the Umpqua, elsewhere,
sow after the danger of frost is over and soil stays over 60[de]F.
If the earth is getting dry by this date, soak the seed overnight
before sowing and furrow down to moist soil. However, do not cover
the seeds more than 2 inches.

_Spacing:_ Twelve to 16 inches apart at final thinning. Allow about
2[f]1/2 to 3 feet on either side of the trellis to avoid root
competition from other plants.

_Irrigation:_ If part of the garden is sprinkler irrigated, space
beans a little tighter and locate the bean trellis toward the outer
reach of the sprinkler's throw. Due to its height, the trellis tends
to intercept quite a bit of water and dumps it at the base. You can
also use the bucket-drip method and fertigate the beans, giving
about 25 gallons per 10 row-feet once or twice during the summer.
Pole beans can make a meaningful yield without any irrigation; under
severe moisture stress they will survive, but bear little.

_Varieties:_ Any of the pole types seem to do fine. Runner beans
seem to prefer cooler locations but are every bit as drought
tolerant as ordinary snap beans. My current favorites are Kentucky
Wonder White Seeded, Fortrex (TSC, JSS), and Musica (TSC).

The older heirloom dry beans were mostly pole types. They are
reasonably productive if allowed to sprawl on the ground without
support. Their unirrigated seed yield is lower, but the seed is
still plump, tastes great, and sprouts well. Compared to unirrigated
Black Coco (TSC), which is my most productive and best-tasting bush
cultivar, Kentucky Wonder Brown Seeded (sometimes called Old
Homestead) (STK, PEA, ABL) yields about 50 percent more seed and
keeps on growing for weeks after Coco has quit. Do not bother to
fertigate untrellised pole beans grown for dry seed. With the threat
of September moisture always looming over dry bean plots, we need to
encourage vines to quit setting and dry down. Peace Seeds and
Abundant Life offer long lists of heirloom vining dry bean
varieties.

Serious self-sufficiency buffs seeking to produced their own legume
supply should also consider the fava, garbanzo bean, and Alaska pea.
Many favas can be overwintered: sow in October, sprout on fall
rains, grow over the winter, and dry down in June with the soil.
Garbanzos are grown like mildly frost-tolerant peas. Alaska peas are
the type used for pea soup. They're spring sown and grown like
ordinary shelling peas. Avoid overhead irrigation while seeds are
drying down.


Beets

Beets will root far deeper and wider than most people realize--in
uncompacted, nonacid soils. Double or triple dig the subsoil
directly below the seed row.

_Sowing date:_ Early April at Elkton, late March farther south, and
as late as April 30 in British Columbia. Beet seed germinates easily
in moist, cool soil. A single sowing may be harvested from June
through early March the next year. If properly thinned, good
varieties remain tender.

_Spacing:_ A single row will gradually exhaust subsoil moisture from
an area 4 feet wide. When the seedlings are 2 to 3 inches tall, thin
carefully to about 1 inch apart. When the edible part is radish
size, thin to 2 inches apart and eat the thinings, tops and all.
When they've grown to golfball size, thin to 4 inches apart, thin
again. When they reach the size of large lemons, thin to 1 foot
apart. Given this much room and deep, open soil, the beets will
continue to grow through the entire summer. Hill up some soil over
the huge roots early in November to protect them from freezing.

_Irrigation:_ Probably not necessary with over 4 feet of deep, open
soil.

_Varieties:_ I've done best with Early Wonder Tall Top; when large,
it develops a thick, protective skin and retains excellent eating
quality. Winterkeepers, normally sown in midsummer with irrigation,
tend to bolt prematurely when sown in April.


Broccoli: Italian Style

Italian-style broccoli needs abundant moisture to be tender and make
large flowers. Given enough elbow room, many varieties can endure
long periods of moisture stress, but the smaller, woody,
slow-developing florets won't be great eating. Without any
irrigation, spring-sown broccoli may still be enjoyed in early
summer and Purple Sprouting in March/April after overwintering.

_Sowing date:_Without any irrigation at all, mid-March through early
April. With fertigation, also mid-April through mid-May. This later
sowing will allow cutting through summer.

_Spacing:_ Brocoli tastes better when big plants grow big, sweet
heads. Allow a 4-foot-wide row. Space early sowings about 3 feet
apart in the row; later sowings slated to mature during summer's
heat can use 4 feet. On a fist-sized spot compacted to restore
capillarity, sow a little pinch of seed atop a well-and deeply
fertilized, double-dug patch of earth. Thin gradually to the best
single plant by the time three or four true leaves have developed.

_Irrigation:_ After mid-June, 4 to 5 gallons of drip bucket liquid
fertilizer every two to three weeks makes an enormous difference.
You'll be surprised at the size of the heads and the quality of side
shoots. A fertigated May sowing will be exhausted by October. Take a
chance: a heavy side-dressing of strong compost or complete organic
fertilizer when the rains return may trigger a massive spurt of new,
larger heads from buds located below the soil's surface.

_Varieties:_ Many hybrids have weak roots. I'd avoid anything that
was "held up on a tall stalk" for mechanical harvest or was
"compact" or that "didn't have many side-shoots". Go for larger
size. Territorial's hybrid blend yields big heads for over a month
followed by abundant side shoots. Old, open-pollinated types like
Italian Sprouting Calabrese, DeCicco, or Waltham 29 are highly
variable, bushy, with rather coarse, large-beaded flowers,
second-rate flavor and many, many side shoots. Irrigating gardeners
who can start new plants every four weeks from May through July may
prefer hybrids. Dry gardeners who will want to cut side shoots for
as long as possible during summer from large, well-established
plants may prefer crude, open-pollinated varieties. Try both.


Broccoli: Purple Sprouting and Other Overwintering Types

_Spacing:_ Grow like broccoli, 3 to 4 feet apart.

_Sowing date:_ It is easiest to sow in April or early May, minimally
fertigate a somewhat gnarly plant through the summer, push it for
size in fall and winter, and then harvest it next March. With too
early a start in spring, some premature flowering may occur in
autumn; still, massive blooming will resume again in spring.

Overwintering green Italian types such as ML423 (TSC) will flower in
fall if sown before late June. These sorts are better started in a
nursery bed around August 1 and like overwintered cauliflower,
transplanted about 2 feet apart when fall rains return, then, pushed
for growth with extra fertilizer in fall and winter.

With nearly a whole year to grow before blooming, Purple Sprouting
eventually reaches 4 to 5 feet in height and 3 to 4 feet in
diameter, and yields hugely.

_Irrigation:_ It is not essential to heavily fertigate Purple
Sprouting, though you may G-R-O-W enormous plants for their beauty.
Quality or quantity of spring harvest won't drop one bit if the
plants become a little stunted and gnarly in summer, as long as you
fertilize late in September to spur rapid growth during fall and
winter.


Root System Vigor in the Cabbage Family

Wild cabbage is a weed and grows like one, able to successfully
compete for water against grasses and other herbs. Remove all
competition with a hoe, and allow this weed to totally control all
the moisture and nutrients in all the earth its roots can occupy,
and it grows hugely and lushly. Just for fun, I once G-R-E-W one,
with tillage, hoeing, and spring fertilization but no irrigation; it
ended up 5 feet tall and 6 feet in diameter.

As this highly moldable family is inbred and shaped into more and
more exaggerated forms, it weakens and loses the ability to forage.
Kale retains the most wild aggressiveness, Chinese cabbage perhaps
the least. Here, in approximately correct order, is shown the
declining root vigor and general adaptation to moisture stress of
cabbage family vegetables. The table shows the most vigorous at the
top, declining as it goes down.


  Adapted to dry gardening           Not vigorous enough

  Kale                               Italian broccoli (some varieties)
  Brussels sprouts (late types)      Cabbage (regular market types)
  Late savoy cabbage                 Brussels sprouts (early types)
  Giant "field-type" kohlrabi        Small "market-garden" kohlrabi
  Mid-season savoy cabbage           Cauliflower (regular, annual)
  Rutabaga                           Turnips and radishes
  Italian Broccoli (some varieties)  Chinese cabbage
  Brussels Sprouts


_Sowing date:_ If the plants are a foot tall before the soil starts
drying down, their roots will be over a foot deep; the plants will
then grow hugely with a bit of fertigation. At Elkton I dry garden
Brussels sprouts by sowing late April to early May. Started this
soon, even late-maturing varieties may begin forming sprouts by
September. Though premature bottom sprouts will "blow up" and become
aphid damaged, more, higher-quality sprouts will continue to form
farther up the stalk during autumn and winter.

_Spacing:_ Make each spot about 4 feet apart.

_Irrigation:_ Without any added moisture, the plants will become
stunted but will survive all summer. Side-dressing manure or
fertilizer late in September (or sooner if the rains come sooner)
will provoke very rapid autumn growth and a surprisingly large yield
from plants that looked stress out in August. If increasingly larger
amounts of fertigation can be provided every two to three weeks, the
lush Brussels sprouts plants can become 4 feet in diameter and 4
feet tall by October and yield enormously.

_Varieties:_ Use late European hybrid types. At Elkton, where
winters are a little milder than in the Willamette, Lunet (TSC) has
the finest eating qualities. Were I farther north I'd grow hardier
types like Stabolite (TSC) or Fortress (TSC). Early types are not
suitable to growing with insufficient irrigation or frequent
spraying to fight off aphids.


Cabbage

Forget those delicate, green supermarket cabbages unless you have
unlimited amounts of water. But easiest-to-grow savoy types will do
surprisingly well with surprisingly little support. Besides, savoys
are the best salad material.

_Sowing date:_ I suggest three sowing times: the first, a succession
of early, midseason, and late savoys made in mid-March for harvest
during summer; the second, late and very late varieties started late
April to early May for harvest during fall and winter; the last, a
nursery bed of overwintered sorts sown late in August.

_Spacing:_ Early-maturing savoy varieties are naturally smaller and
may not experience much hot weather before heading up--these may be
separated by about 30 inches. The later ones are large plants and
should be given 4 feet of space or 16 square feet of growing room.
Sow and grow them like broccoli. Transplant overwintered cabbages
from nursery beds late in October, spaced about 3 feet apart; these
thrive where the squash grew.

_Irrigation:_ The more fertigation you can supply, the larger and
more luxuriant the plants and the bigger the heads. But even small,
somewhat moisture-stressed savoys make very edible heads. In terms
of increased yield for water expended, it is well worth it to
provide late varieties with a few gallons of fertigation about
mid-June, and a bucketful in mid-July and mid-August.

_Varieties:_ Japanese hybrid savoys make tender eating but may not
withstand winter. European savoys are hardier, coarser,
thicker-leaved, and harder chewing. For the first sowing I suggest a
succession of Japanese varieties including Salarite or Savoy
Princess for earlies; Savoy Queen, King, or Savoy Ace for midsummer;
and Savonarch (TSC) for late August/early September harvests.
They're all great varieties. For the second sowing I grow Savonarch
(TSC) for September[-]November cutting and a very late European
hybrid type like Wivoy (TSC) for winter. Small-framed January King
lacks sufficient root vigor. Springtime (TSC) and FEM218 (TSC) are
the only overwintered cabbages available.


Carrots

Dry-gardening carrots requires patiently waiting until the weather
stabilizes before tilling and sowing. To avoid even a little bit of
soil compaction, I try to sprout the seed without irrigation but
always fear that hot weather will frustrate my efforts. So I till
and plant too soon. And then heavy rain comes and compacts my
perfectly fluffed-up soil. But the looser and finer the earth
remains during their first six growing weeks, the more perfectly the
roots will develop.

_Sowing date:_ April at Elkton.

_Spacing:_ Allocate 4 feet of width to a single row of carrot seed.
When the seedlings are about 2 inches tall, thin to 1 inch apart.
Then thin every other carrot when the roots are [f]3/8 to [f]1/2
inch in diameter and eat the thinnings. A few weeks later, when the
carrots are about 3/4 to 1 inch in diameter, make a final thinning
to 1 foot apart.

_Irrigation:_ Not necessary. Foliar feeding every few weeks will
make much larger roots. Without any help they should grow to several
pounds each.

_Varieties:_ Choosing the right variety is very important. Nantes
and other delicate, juicy types lack enough fiber to hold together
when they get very large. These split prematurely. I've had my best
results with Danvers types. I'd also try Royal Chantenay (PEA),
Fakkel Mix (TSC), Stokes "Processor" types, and Topweight (ABL). Be
prepared to experiment with variety. The roots will not be quite as
tender as heavily watered Nantes types but are a lot better than
you'd think. Huge carrots are excellent in soups and we cheerfully
grate them into salads. Something about accumulating sunshine all
summer makes the roots incredibly sweet.


Cauliflower

Ordinary varieties cannot forage for moisture. Worse, moisture
stress at any time during the growth cycle prevents proper formation
of curds. The only important cauliflowers suitable for dry gardening
are overwintered types. I call them important because they're easy
to grow and they'll feed the family during April and early May, when
other garden fare is very scarce.

_Sowing date:_ To acquire enough size to survive cold weather,
overwintered cauliflower must be started on a nursery bed during the
difficult heat of early August. Except south of Yoncalla, delaying
sowing until September makes very small seedlings that may not be
hardy enough and likely won't yield much in April unless winter is
very mild, encouraging unusual growth.

_Spacing:_ In October, transplant about 2 feet apart in rows 3 to 4
feet apart.

_Irrigation:_ If you have more water available, fertilize and till
up some dusty, dry soil, wet down the row, direct-seed like broccoli
(but closer together), and periodically irrigate until fall. If you
only moisten a narrow band of soil close to the seedlings it won't
take much water. Cauliflower grows especially well in the row that
held bush peas.

_Varieties:_ The best are the very pricy Armado series sold by
Territorial.


Chard

This vegetable is basically a beet with succulent leaves and thick
stalks instead of edible, sweet roots. It is just as drought
tolerant as a beet, and in dry gardening, chard is sown, spaced, and
grown just like a beet. But if you want voluminous leaf production
during summer, you may want to fertigate it occasionally.

_Varieties:_ The red chards are not suitable for starting early in
the season; they have a strong tendency to bolt prematurely if sown
during that part of the year when daylength is increasing.


Corn

Broadcast complete organic fertilizer or strong compost shallowly
over the corn patch till midwinter, or as early in spring as the
earth can be worked without making too many clods. Corn will
germinate in pretty rough soil. High levels of nutrients in the
subsoil are more important than a fine seedbed.

_Sowing date:_ About the time frost danger ends. Being large seed,
corn can be set deep, where soil moisture still exists even after
conditions have warmed up. Germination without irrigation should be
no problem.

_Spacing_: The farther south, the farther apart. Entirely without
irrigation, I've had fine results spacing individual corn plants 3
feet apart in rows 3 feet apart, or 9 square feet per each plant.
Were I around Puget Sound or in B.C. I'd try 2 feet apart in rows 30
inches apart. Gary Nabhan describes Papago gardeners in Arizona
growing individual cornstalks 10 feet apart. Grown on wide spacings,
corn tends to tiller (put up multiple stalks, each making one or two
ears). For most urban and suburban gardeners, space is too valuable
to allocate 9 square feet for producing one or at best three or four
ears.

_Irrigation:_ With normal sprinkler irrigation, corn may be spaced 8
inches apart in rows 30 inches apart, still yielding one or two ears
per stalk.

_Varieties:_ Were I a devoted sweetcorn eater without enough
irrigation, I'd be buying a few dozen freshly picked ears from the
back of a pickup truck parked on a corner during local harvest
season. Were I a devoted corn grower without any irrigation, I'd be
experimenting with various types of field corn instead of sweet
corn. Were I a self-sufficiency buff trying earnestly to produce
all my own cereal, I'd accept that the maritime Northwest is a
region where survivalists will eat wheat, rye, millet, and other
small grains.

Many varieties of field corn are nearly as sweet as ordinary sweet
corn, but grain varieties become starchy and tough within hours of
harvest. Eaten promptly, "pig" corn is every bit as tasty as
Jubilee. I've had the best dry-garden results with Northstine Dent
(JSS) and Garland Flint (JSS). Hookers Sweet Indian (TSC) has a weak
root system.


Successfully Starting Cucurbits From Seed

With cucurbits, germination depends on high-enough soil temperature
and not too much moisture. Squash are the most chill and moisture
tolerant, melons the least. Here's a failure-proof and simple
technique that ensures you'll plant at exactly the right time.

Cucumbers, squash, and melons are traditionally sown atop a deeply
dug, fertilized spot that usually looks like a little mound after it
is worked and is commonly called a hill. About two weeks before the
last anticipated frost date in your area, plant five or six squash
seeds about 2 inches deep in a clump in the very center of that
hill. Then, a week later, plant another clump at 12 o'clock. In
another week, plant another clump at 3 o'clock, and continue doing
this until one of the sowings sprouts. Probably the first try won't
come up, but the hill will certainly germinate several clumps of
seedlings. If weather conditions turn poor, a later-to-sprout group
may outgrow those that came up earlier. Thin gradually to the best
single plant by the time the vines are running.

When the first squash seeds appear it is time to begin sowing
cucumbers, starting a new batch each week until one emerges. When
the cucumbers first germinate, it's time to try melons.

Approaching cucurbits this way ensures that you'll get the earliest
possible germination while being protected against the probability
that cold, damp weather will prevent germination or permanently
spoil the growth prospects of the earlier seedlings.


Cucumbers

_Sowing date:_ About May 5 to 15 at Elkton.

_Spacing:_ Most varieties usually run five about 3 feet from the
hill. Space the hills about 5 to 6 feet apart in all directions.

_Irrigation:_ Like melons. Regular and increasing amounts of
fertigation will increase the yield several hundred percent.

_Varieties:_ I've had very good results dry-gardening Amira II
(TSC), even without any fertigation at all. It is a Middle
Eastern[-]style variety that makes pickler-size thin-skinned cukes
that need no peeling and have terrific flavor. The burpless or
Japanese sorts don't seem to adapt well to drought. Most slicers
dry-garden excellently. Apple or Lemon are similar novelty heirlooms
that make very extensive vines with aggressive roots and should be
given a foot or two more elbow room. I'd avoid any variety touted as
being for pot or patio, compact, or short-vined, because of a likely
linkage between its vine structure and root system.


Eggplant

Grown without regular sprinkler irrigation, eggplant seems to get
larger and yield sooner and more abundantly. I suspect this delicate
and fairly drought-resistant tropical species does not like having
its soil temperature lowered by frequent watering.

_Sowing date:_ Set out transplants at the usual time, about two
weeks after the tomatoes, after all frost danger has passed and
after nights have stably warmed up above 50 degree F.

_Spacing:_ Double dig and deeply fertilize the soil under each
transplant. Separate plants by about 3 feet in rows about 4 feet
apart.

_Irrigation:_ Will grow and produce a few fruit without any
watering, but a bucket of fertigation every three to four weeks
during summer may result in the most luxurious, hugest, and
heaviest-bearing eggplants you've ever grown.

_Varieties:_ I've noticed no special varietal differences in ability
to tolerate dryish soil. I've had good yields from the regionally
adapted varieties Dusky Hybrid, Short Tom, and Early One.


Endive

A biennial member of the chicory family, endive quickly puts down a
deep taproot and is naturally able to grow through prolonged
drought. Because endive remains bitter until cold weather, it
doesn't matter if it grows slowly through summer, just so long as
rapid leaf production resumes in autumn.

_Sowing date:_ On irrigated raised beds endive is sown around August
1 and heads by mid-October. The problem with dry-gardened endive is
that if it is spring sown during days of increasing daylength when
germination of shallow-sown small seed is a snap, it will bolt
prematurely. The crucial moment seems to be about June 1. April/May
sowings bolt in July/August,: after June 1, bolting won't happen
until the next spring, but germination won't happen without
watering. One solution is soaking the seeds overnight, rinsing them
frequently until they begin to sprout, and fluid drilling them.

_Spacing:_ The heads become huge when started in June. Sow in rows 4
feet apart and thin gradually until the rosettes are 3 inches in
diameter, then thin to 18 inches apart.

_Irrigation:_ Without a drop of moisture the plants, even as tiny
seedlings, will grow steadily but slowly all summer, as long as no
other crop is invading their root zone. The only time I had trouble
was when the endive row was too close to an aggressive row of yellow
crookneck squash. About August, the squash roots began invading the
endive's territory and the endive got wilty.

A light side-dressing of complete organic fertilizer or compost in
late September will grow the hugest plants imaginable.

_Varieties:_ Curly types seem more tolerant to rain and frost during
winter than broad-leaf Batavian varieties. I prefer President (TSC).


Herbs

Most perennial and biennial herbs are actually weeds and wild
hillside shrubs from Mediterranean climates similar to that of
Southern California. They are adapted to growing on winter rainfall
and surviving seven to nine months without rainfall every summer. In
our climate, merely giving them a little more elbow room than
usually offered, thorough weeding, and side-dressing the herb garden
with a little compost in fall is enough coddling. Annuals such as
dill and cilantro are also very drought tolerant. Basil, however,
needs considerable moisture.


Kale

Depending on the garden for a significant portion of my annual
caloric intake has gradually refined my eating habits. Years ago I
learned to like cabbage salads as much as lettuce. Since lettuce
freezes out many winters (19-21 degree F), this adjustment has proved
very useful. Gradually I began to appreciate kale, too, and now
value it as a salad green far more than cabbage. This personal
adaptation has proved very pro-survival, because even savoy cabbages
do not grow as readily or yield nearly as much as kale. And kale is
a tad more cold hardy than even savoy cabbage.

You may be surprised to learn that kale produces more complete
protein per area occupied per time involved than any legume,
including alfalfa. If it is steamed with potatoes and then mashed,
the two vegetables complement and flavor each other. Our region
could probably subsist quite a bit more healthfully than at present
on potatoes and kale. The key to enjoying kale as a salad component
is varietal choice, preparation, and using the right parts of the
plant. Read on.

_Sowing date:_ With irrigation, fast-growing kale is usually started
in midsummer for use in fall and winter. But kale is absolutely
biennial--started in March or April, it will not bolt until the next
spring. The water-wise gardener can conveniently sow kale while
cool, moist soil simplifies germination. Starting this early also
produces a deep root system before the soil dries much, and a much
taller, very useful central stalk on oleracea types, while early
sown Siberian (Napa) varieties tend to form multiple rosettes by
autumn, also useful at harvest time.

_Spacing: _Grow like broccoli, spaced 4 feet apart.

_Irrigation:_ Without any water, the somewhat stunted plants will
survive the summer to begin rapid growth as soon as fall rains
resume. With the help of occasional fertigation they grow lushly and
are enormous by September. Either way, there still will be plenty of
kale during fall and winter.

_Harvest:_ Bundles of strong-flavored, tough, large leaves are sold
in supermarkets but are the worst-eating part of the plant. If
chopped finely enough, big raw leaves can be masticated and
tolerated by people with good teeth. However, the tiny leaves are
far tenderer and much milder. The more rosettes developed on
Siberian kales, the more little leaves there are to be picked. By
pinching off the central growing tip in October and then gradually
stripping off the large shading leaves, _oleracea_ varieties may be
encouraged to put out dozens of clusters of small, succulent leaves
at each leaf notch along the central stalk. The taller the stalk
grown during summer, the more of these little leaves there will be.
Only home gardeners can afford the time to hand pick small leaves.

_Varieties:_ I somewhat prefer the flavor of Red Russian to the
ubiquitous green Siberian, but Red Russian is very slightly less
cold hardy. Westland Winter (TSC) and Konserva (JSS) are tall
European oleracea varieties. Winterbor F1 (JSS, TSC) is also
excellent. The dwarf "Scotch" kales, blue or green, sold by many
American seed companies are less vigorous types that don't produce
nearly as many gourmet little leaves. Dwarfs in any species tend to
have dwarfed root systems.


Kohlrabi (Giant)

Spring-sown market kohlrabi are usually harvested before hot weather
makes them get woody. Irrigation is not required if they're given a
little extra elbow room. With ordinary varieties, try thinning to 5
inches apart in rows 2 to 3 feet apart and harvest by thinning
alternate plants. Given this additional growing room, they may not
get woody until midsummer. On my irrigated, intensive bed I always
sow some more on August 1, to have tender bulbs in autumn.

Kohlrabi was once grown as European fodder crop; slow-growing
farmers, varieties grow huge like rutabagas. These field types have
been crossed with table types to make "giant" table varieties that
really suit dry gardening. What to do with a giant kohlrabi (or any
bulb getting overblown)? Peel, grate finely, add chopped onion,
dress with olive oil and black pepper, toss, and enjoy this old
Eastern European mainstay.

_Sowing date:_ Sow giant varieties during April, as late as possible
while still getting a foot-tall plant before really hot weather.

_Spacing:_ Thin to 3 feet apart in rows 4 feet apart.

_Irrigation:_ Not absolutely necessary on deep soil, but if they get
one or two thorough fertigations during summer their size may
double.

_Varieties:_ A few American seed companies, including Peace Seeds,
have a giant kohlrabi of some sort or other. The ones I've tested
tend to be woody, are crude, and throw many off-types, a high
percentage of weak plants, and/or poorly shaped roots. By the time
this book is in print, Territorial should list a unique Swiss
variety called Superschmeltz, which is uniformly huge and stays
tender into the next year.


Leeks

Unwatered spring-sown bulbing onions are impossible. Leek is the
only allium I know of that may grow steadily but slowly through
severe drought; the water-short gardener can depend on leeks for a
fall/winter onion supply.

_Sowing date:_ Start a row or several short rows about 12 inches
apart on a nursery bed in March or early April at the latest. Grow
thickly, irrigate during May/June, and fertilize well so the
competing seedlings get leggy.

_Spacing:_ By mid-to late June the seedlings should be slightly
spindly, pencil-thick, and scallion size. With a sharp shovel, dig
out the nursery row, carefully retaining 5 or 6 inches of soil below
the seedlings. With a strong jet of water, blast away the soil and,
while doing this, gently separate the tangled roots so that as
little damage is done as possible. Make sure the roots don't dry out
before transplanting. After separation, I temporarily wrap bundled
seedlings in wet newspaper.

Dig out a foot-deep trench the width of an ordinary shovel and
carefully place this earth next to the trench. Sprinkle in a heavy
dose of organic fertilizer or strong compost, and spade that in so
the soil is fluffy and fertile 2 feet down. Do not immediately
refill the trench with the soil that was dug out. With a shovel
handle, poke a row of 6-inch-deep holes along the bottom of the
trench. If the nursery bed has grown well there should be about 4
inches of stem on each seedling before the first leaf attaches. If
the weather is hot and sunny, snip off about one-third to one-half
the leaf area to reduce transplanting shock. Drop one leek seedling
into each hole up to the point that the first leaf attaches to the
stalk, and mud it in with a cup or two of liquid fertilizer. As the
leeks grow, gradually refill the trench and even hill up soil around
the growing plants. This makes the better-tasting white part of the
stem get as long as possible. Avoid getting soil into the center of
the leek where new leaves emerge, or you'll not get them clean after
harvest.

Spacing of the seedlings depends on the amount of irrigation. If
absolutely none at all, set them 12 inches apart in the center of a
row 4 feet wide. If unlimited water is available, give them 2 inches
of separation. Or adjust spacing to the water available. The plants
grow slowly through summer, but in autumn growth will accelerate,
especially if they are side-dressed at this time.

_Varieties:_ For dry gardening use the hardier, more vigorous winter
leeks. Durabel (TSC) has an especially mild, sweet flavor. Other
useful varieties include Giant Carentian (ABL), Alaska (STK), and
Winter Giant (PEA).


Lettuce

Spring-sown lettuce will go to large sizes, remaining sweet and
tender without irrigation if spaced 1 foot apart in a single row
with 2 feet of elbow room on each side. Lettuce cut after mid-June
usually gets bitter without regular, heavy irrigation. I reserve my
well-watered raised bed for this summer salad crop. Those very short
of water can start fall/winter lettuce in a shaded, irrigated
nursery bed mid-August through mid-September and transplant it out
after the fall rains return. Here is one situation in which
accelerating growth with cloches or cold frames would be very
helpful.


Water-Wise Cucurbits

The root systems of this family are far more extensive than most
people realize. Usually a taproot goes down several feet and then,
soil conditions permitting, thickly occupies a large area,
ultimately reaching down 5 to 8 feet. Shallow feeder roots also
extend laterally as far as or farther than the vines reach at their
greatest extent.

Dry gardeners can do several things to assist cucurbits. First, make
sure there is absolutely no competition in their root zone. This
means[i]one plant per hill, with the hills separated in all
directions a little farther than the greatest possible extent of the
variety's ultimate growth.[i] Common garden lore states that
squashes droop their leaves in midsummer heat and that this trait
cannot be avoided and does no harm. But if they've grown as
described above, on deep, open soil, capillarity and surface
moisture reserves ensure there usually will be no midday wilting,
even if there is no watering. Two plants per hill do compete and
make each other wilt.

Second, double dig and fertilize the entire lateral root zone.
Third, as much as possible, avoid walking where the vines will
ultimately reach to avoid compaction. Finally, [i]do not transplant
them.[i] This breaks the taproot and makes the plant more dependent
on lateral roots seeking moisture in the top 18 inches of soil.


Melons

_Sowing date:_ As soon as they'll germinate outdoors: at Elkton, May
15 to June 1. Thin to a single plant per hill when there are about
three true leaves and the vines are beginning to run.

_Spacing:_ Most varieties will grow a vine reaching about 8 feet in
diameter. Space the hills 8 feet apart in all directions.

_Irrigation:_ Fertigation every two to three weeks will increase the
yield by two or three times and may make the melons sweeter. Release
the water/fertilizer mix close to the center of the vine, where the
taproot can use it.

_Varieties:_ Adaptation to our cool climate is critical with melons;
use varieties sold by our regional seed companies. Yellow Doll
watermelons (TSC) are very early and seem the most productive under
the most droughty conditions. I've had reasonable results from most
otherwise regionally adapted cantaloupes and muskmelons. Last year a
new hybrid variety, Passport (TSC), proved several weeks earlier
than I'd ever experienced and was extraordinarily prolific and
tasty.


Onions/Scallions

The usual spring-sown, summer-grown bulb onions and scallions only
work with abundant irrigation. But the water-short, water-wise
gardener can still supply the kitchen with onions or onion
substitutes year-round. Leeks take care of November through early
April. Overwintered bulb onions handle the rest of the year.
Scallions may also be harvested during winter.

_Sowing date:_ Started too soon, overwintered or short-day bulbing
onions (and sweet scallions) will bolt and form seed instead of
bulbing. Started too late they'll be too small and possibly not
hardy enough to survive winter. About August 15 at Elkton I sow
thickly in a well-watered and very fertile nursery bed. If you have
more than one nursery row, separate them about by 12 inches. Those
who miss this window of opportunity can start transplants in early
October and cover with a cloche immediately after germination, to
accelerate seedling growth during fall and early winter.

Start scallions in a nursery just like overwintered onions, but
earlier so they're large enough for the table during winter, I sow
them about mid-July.

_Spacing:_ When seedlings are about pencil thick (December/January
for overwintering bulb onions), transplant them about 4 or 5 inches
apart in a single row with a couple of feet of elbow room on either
side. I've found I get the best growth and largest bulbs if they
follow potatoes. After the potatoes are dug in early October I
immediately fertilize the area heavily and till, preparing the onion
bed. Klamath Basin farmers usually grow a similar rotation: hay,
potatoes, onions.

Transplant scallions in October with the fall rains, about 1 inch
apart in rows at least 2 feet apart.

_Irrigation:_ Not necessary. However, side-dressing the transplants
will result in much larger bulbs or scallions. Scallions will bolt
in April; the bulbers go tops-down and begin drying down as the soil
naturally dries out.

_Varieties:_ I prefer the sweet and tender Lisbon (TSC) for
scallions. For overwintered bulb onions, grow very mild but poorly
keeping Walla Walla Sweet (JSS), Buffalo (TSC), a better keeper, or
whatever Territorial is selling at present.


Parsley

_Sowing date:_ March. Parsley seed takes two to three weeks to
germinate.

_Spacing:_ Thin to 12 inches apart in a single row 4 feet wide. Five
plants should overwhelm the average kitchen.

_Irrigation:_ Not necessary unless yield falls off during summer and
that is very unlikely. Parsley's very deep, foraging root system
resembles that of its relative, the carrot.

_Varieties:_ If you use parsley for greens, variety is not critical,
though the gourmet may note slight differences in flavor or amount
of leaf curl. Another type of parsley is grown for edible roots that
taste much like parsnip. These should have their soil prepared as
carefully as though growing carrots.


Peas

This early crop matures without irrigation. Both pole and bush
varieties are planted thickly in single rows about 4 feet apart. I
always overlook some pods, which go on to form mature seed. Without
overhead irrigation, this seed will sprout strongly next year.
Alaska (soup) peas grow the same way.


Peppers

Pepper plants on raised beds spaced the usually recommended 16 to 24
inches apart undergo intense root competition even before their
leaves form a canopy. With or without unlimited irrigation, the
plants will get much larger and bear more heavily with elbow room.

_Sowing date:_ Set out transplants at the usual time. Double dig a
few square feet of soil beneath each seedling, and make sure
fertilizer gets incorporated all the way down to 2 feet deep.

_Spacing:_ Three feet apart in rows 3 to 4 feet apart.

_Irrigation:_ Without any irrigation only the most vigorous,
small-fruited varieties will set anything. For an abundant harvest,
fertigate every three or four weeks. For the biggest pepper plants
you ever grew, fertigate every two weeks.

_Varieties:_ The small-fruited types, both hot and sweet, have much
more aggressive root systems and generally adapt better to our
region's cool weather. I've had best results with Cayenne Long Slim,
Gypsie, Surefire, Hot Portugal, the "cherries" both sweet and hot,
Italian Sweet, and Petite Sirah.


Potatoes

Humans domesticated potatoes in the cool, arid high plateaus of the
Andes where annual rainfall averages 8 to 12 inches. The species
finds our dry summer quite comfortable. Potatoes produce more
calories per unit of land than any other temperate crop. Irrigated
potatoes yield more calories and two to three times as much watery
bulk and indigestible fiber as those grown without irrigation, but
the same variety dry gardened can contain about 30 percent more
protein, far more mineral nutrients, and taste better.

_Sowing date:_ I make two sowings. The first is a good-luck ritual
done religiously on March 17th--St. Patrick's Day. Rain or shine, in
untilled mud or finely worked and deeply fluffed earth, I still
plant 10 or 12 seed potatoes of an early variety. This provides for
summer.

The main sowing waits until frost is unlikely and I can dig the
potato rows at least 12 inches deep with a spading fork, working in
fertilizer as deeply as possible and ending up with a finely
pulverized 24-inch-wide bed. At Elkton, this is usually mid-to late
April. There is no rush to plant. Potato vines are not frost hardy.
If frosted they'll regrow, but being burned back to the ground
lowers the final yield.

_Spacing:_ I presprout my seeds by spreading them out in daylight at
room temperature for a few weeks, and then plant one whole,
sprouting, medium-size potato every 18 inches down the center of the
row. Barely cover the seed potato. At maturity there should be
2[f]1/2 to 3 feet of soil unoccupied with the roots of any other
crop on each side of the row. As the vines emerge, gradually scrape
soil up over them with a hoe. Let the vines grow about 4 inches,
then pull up about 2 inches of cover. Let another 4 inches grow,
then hill up another 2 inches. Continue doing this until the vines
begin blooming. At that point there should be a mound of loose,
fluffy soil about 12 to 16 inches high gradually filling with tubers
lushly covered with blooming vines.

_Irrigation:_ Not necessary. In fact, if large water droplets
compact the loose soil you scraped up, that may interfere with
maximum tuber enlargement. However, after the vines are a foot long
or so, foliar feeding every week or 10 days will increase the yield.

_Varieties:_ The water-wise gardener's main potato problem is
too-early maturity, and then premature sprouting in storage. Early
varieties like Yukon Gold--even popular midseason ones like Yellow
Finn--don't keep well unless they're planted late enough to brown
off in late September. That's no problem if they're irrigated. But
planted in late April, earlier varieties will shrivel by August.
Potatoes only keep well when very cool, dark, and moist--conditions
almost impossible to create on the homestead during summer. The best
August compromise is to leave mature potatoes undug, but soil
temperatures are in the 70s during August, and by early October,
when potatoes should be lifted and put into storage, they'll already
be sprouting. Sprouting in October is acceptable for the remainders
of my St. Pat's Day sowing that I am keeping over for seed next
spring. It is not ok for my main winter storage crop. Our climate
requires very late, slow-maturing varieties that can be sown early
but that don't brown off until September. Late types usually yield
more, too.

Most of the seed potato varieties found in garden centers are early
or midseason types chosen by farmers for yield without regard to
flavor or nutrition. One, Nooksack Cascadian, is a very late variety
grown commercially around Bellingham, Washington. Nooksack is pretty
good if you like white, all-purpose potatoes.

There are much better homegarden varieties available in Ronniger's
catalog, all arranged according to maturity. For the ultimate in
earlies I suggest Red Gold. For main harvests I'd try Indian Pit,
Carole, German Butterball, Siberian, or a few experimental row-feet
of any other late variety taking your fancy.


Rutabagas

Rutabagas have wonderfully aggressive root systems and are capable
of growing continuously through long, severe drought. But where I
live, the results aren't satisfactory. Here's what happens. If I
start rutabagas in early April and space them about 2 to 3 feet
apart in rows 4 feet apart, by October they're the size of
basketballs and look pretty good; unfortunately, I harvest a hollow
shell full of cabbage root maggots. Root maggots are at their peak
in early June. That's why I got interested in dry-gardening giant
kohlrabi.

In 1991 we had about 2 surprising inches of rain late in June, so as
a test I sowed rutabagas on July 1. They germinated without more
irrigation, but going into the hot summer as small plants with
limited root systems and no irrigation at all they became somewhat
stunted. By October 1 the tops were still small and a little gnarly;
big roots had not yet formed. Then the rains came and the rutabagas
began growing rapidly. By November there was a pretty nice crop of
medium-size good-eating roots.

I suspect that farther north, where evaporation is not so severe and
midsummer rains are slightly more common, if a little irrigation
were used to start rutabagas about July 1, a decent unwatered crop
might be had most years. And I am certain that if sown at the normal
time (July 15) and grown with minimal irrigation but well spaced
out, they'll produce acceptably.

_Varieties:_ Stokes Altasweet (STK, TSC) has the best flavor.


Sorrel

This weed-like, drought-tolerant salad green is little known and
underappreciated. In summer the leaves get tough and strong
flavored; if other greens are available, sorrel will probably be
unpicked. That's ok. During fall, winter, and spring, sorrel's
lemony taste and delicate, tender texture balance tougher savoy
cabbage and kale and turn those crude vegetables into very
acceptable salads. Serious salad-eating families might want the
production of 5 to 10 row-feet.

_Sowing date:_ The first year you grow sorrel, sow mid-March to
mid-April. The tiny seed must be placed shallowly, and it sprouts
much more readily when the soil stays moist. Plant a single furrow
centered in a row 4 feet wide.

_Spacing: _As the seedlings grow, thin gradually. When the leaves
are about the size of ordinary spinach, individual plants should be
about 6 inches apart.

_Irrigation:_ Not necessary in summer--you won't eat it anyway. If
production lags in fall, winter, or spring, side-dress the sorrel
patch with a little compost or organic fertilizer.

_Maintenance:_ Sorrel is perennial. If an unusually harsh winter
freeze kills off the leaves it will probably come back from root
crowns in early spring. You'll welcome it after losing the rest of
your winter crops. In spring of the second and succeeding years
sorrel will make seed. Seed making saps the plant's energy, and the
seeds may naturalize into an unwanted weed around the garden. So,
before any seed forms, cut all the leaves and seed stalks close to
the ground; use the trimmings as a convenient mulch along the row.
If you move the garden or want to relocate the patch, do not start
sorrel again from seed. In any season dig up a few plants, divide
the root masses, trim off most of the leaves to reduce transplanting
shock, and transplant 1 foot apart. Occasional unique plants may be
more reluctant to make seed stalks than most others. Since seed
stalks produce few edible leaves and the leaves on them are very
harsh flavored, making seed is an undesirable trait. So I propagate
only seed-shy plants by root cuttings.


Spinach

Spring spinach is remarkably more drought tolerant than it would
appear from its delicate structure and the succulence of its leaves.
A bolt-resistant, long-day variety bred for summer harvest sown in
late April may still yield pickable leaves in late June or even
early July without any watering at all, if thinned to 12 inches
apart in rows 3 feet apart.


Squash, Winter and Summer

_Sowing date:_ Having warm-enough soil is everything. At Elkton I
first attempt squash about April 15. In the Willamette, May 1 is
usual. Farther north, squash may not come up until June 1. Dry
gardeners should not transplant squash; the taproot must not be
broken.

_Spacing:_ The amount of room to give each plant depends on the
potential of a specific variety's maximum root development. Most
vining winter squash can completely occupy a 10-foot-diameter
circle. Sprawly heirloom summer squash varieties can desiccate an
8-or 9-foot-diameter circle. Thin each hill to one plant, not two or
more as is recommended in the average garden book. There must be no
competition for water.

_Irrigation:_ With winter storage types, an unirrigated vine may
yield 15 pounds of squash after occupying a 10-foot-diameter circle
for an entire growing season. However, starting about July 1, if you
support that vine by supplying liquid fertilizer every two to three
weeks you may harvest 60 pounds of squash from the same area. The
first fertigation may only need 2 gallons. Then mid-July give 4;
about August 1, 8; August 15, feed 15 gallons. After that date,
solar intensity and temperatures decline, growth rate slows, and
water use also decreases. On September 1 I'd add about 8 gallons and
about 5 more on September 15 if it hadn't yet rained significantly.
Total water: 42 gallons. Total increase in yield: 45 pounds. I'd say
that's a good return on water invested.

_Varieties:_ For winter squash, all the vining winter varieties in
the C. maxima or C. pepo family seem acceptably adapted to dry
gardening. These include Buttercup, Hubbard, Delicious, Sweet Meat,
Delicata, Spaghetti, and Acorn. I wouldn't trust any of the newer
compact bush winter varieties so popular on raised beds. Despite
their reputation for drought tolerance C. mixta varieties (or cushaw
squash) were believed to be strictly hot desert or humid-tropical
varieties, unable to mature in our cool climate. However, Pepita
(PEA) is a mixta that is early enough and seems entirely unbothered
by a complete lack of irrigation. The enormous vine sets numerous
good keepers with mild-tasting, light yellow flesh.

Obviously, the compact bush summer squash varieties so popular these
days are not good candidates for withstanding long periods without
irrigation. The old heirlooms like Black Zucchini (ABL) (not Black
Beauty!) and warty Yellow Crookneck grow enormous, high-yielding
plants whose extent nearly rivals that of the largest winter squash.
They also grow a dense leaf cover, making the fruit a little harder
to find. These are the only American heirlooms still readily
available. Black Zucchini has become very raggedy; anyone growing it
should be prepared to plant several vines and accept that at least
one-third of them will throw rather off-type fruit. It needs the
work of a skilled plant breeder. Yellow Crookneck is still a fairly
"clean" variety offering good uniformity. Both have more flavor and
are less watery than the modern summer squash varieties. Yellow
Crookneck is especially rich, probably due to its thick, oily skin;
most gardeners who once grow the old Crookneck never again grow any
other kind. Another useful drought-tolerant variety is Gem,
sometimes called Rolet (TSC). It grows an extensive
winter-squash-like vine yielding grapefruit-size, excellent eating
summer squash.

Both Yellow Crookneck and Black Zucchini begin yielding several
weeks later than the modern hybrids. However, as the summer goes on
they will produce quite a bit more squash than new hybrid types. I
now grow five or six fully irrigated early hybrid plants like Seneca
Zucchini too. As soon as my picking bucket is being filled with
later-to-yield Crooknecks, I pull out the Senecas and use the now
empty irrigated space for fall crops.


Tomato

There's no point in elaborate methods--trellising, pruning, or
training--with dry-gardened tomato vines. Their root systems must be
allowed to control all the space they can without competition, so
allow the vines to sprawl as well. And pruning the leaf area of
indeterminates is counterproductive: to grow hugely, the roots need
food from a full complement of leaves.

_Sowing date:_ Set out transplants at the usual time. They might
also be jump started under cloches two to three weeks before the
last frost, to make better use of natural soil moisture.

_Spacing:_ Depends greatly on variety. The root system can occupy as
much space as the vines will cover and then some.

_Irrigation:_ Especially on determinate varieties, periodic
fertigation will greatly increase yield and size of fruit. The old
indeterminate sprawlers will produce through an entire summer
without any supplemental moisture, but yield even more in response
to irrigation.

_Variety:_ With or without irrigation or anywhere in between, when
growing tomatoes west of the Cascades, nothing is more important
than choosing the right variety. Not only does it have to be early
and able to set and ripen fruit when nights are cool, but to grow
through months without watering the plant must be highly
indeterminate. This makes a built-in conflict: most of the sprawly,
huge, old heirloom varieties are rather late to mature. But cherry
tomatoes are always far earlier than big slicers.

If I had to choose only one variety it would be the old heirloom
[Large] Red Cherry. A single plant is capable of covering a 9- to
10-foot-diameter circle if fertigated from mid-July through August.
The enormous yield of a single fertigated vine is overwhelming.

Red Cherry is a little acid and tart. Non-acid, indeterminate cherry
types like Sweetie, Sweet 100, and Sweet Millions are also workable
but not as aggressive as Red Cherry. I wouldn't depend on most bush
cherry tomato varieties. But our earliest cherry variety of all,
OSU's Gold Nugget, must grow a lot more root than top, for, with or
without supplemental water, Gold Nugget sets heavily and ripens
enormously until mid-August, when it peters out from overbearing
(not from moisture stress). Gold Nugget quits just about when the
later cherry or slicing tomatoes start ripening heavily.

Other well-adapted early determinates such as Oregon Spring and
Santiam may disappoint you. Unless fertigated, they'll set and ripen
some fruit but may become stunted in midsummer. However, a single
indeterminate Fantastic Hybrid will cover a 6-to 7-foot-diameter
circle, and grow and ripen tomatoes until frost with only a minimum
of water. I think Stupice (ABL, TSC) and Early Cascade are also
quite workable (and earlier than Fantastic in Washington).




Chapter 6

My Own Garden Plan


This chapter illustrates and explains my own dry garden. Any garden
plan is a product of compromises and preferences; mine is not
intended to become yours. But, all modesty aside, this plan results
from 20 continuous years of serious vegetable gardening and some
small degree of regional wisdom.

My wife and I are what I dub "vegetablitarians." Not vegetarians, or
lacto-ovo vegetarians because we're not ideologues and eat meat on
rare, usually festive occasions in other peoples' houses. But over
80 percent of our calories are from vegetable, fruit, or cereal
sources and the remaining percentage is from fats or dairy foods.
The purpose of my garden is to provide at least half the actual
calories we eat year-round; most of the rest comes from home-baked
bread made with freshly ground whole grains. I put at least one very
large bowl of salad on the table every day, winter and summer. I
keep us in potatoes nine months a year and produce a year's supply
of onions or leeks. To break the dietary monotony of November to
April, I grow as wide an assortment of winter vegetables as possible
and put most produce departments to shame from June through
September, when the summer vegies are "on."

The garden plan may seem unusually large, but in accordance with
Solomon's First Law of Abundance, there's a great deal of
intentional waste. My garden produces two to three times the amount
of food needed during the year so moochers, poachers, guests, adult
daughters accompanied by partners, husbands, and children, mistakes,
poor yields, and failures of individual vegetables are
inconsequential. Besides, gardening is fun.

My garden is laid out in 125-foot-long rows and one equally long
raised bed. Each row grows only one or two types of vegetables. The
central focus of my water-wise garden is its irrigation system. Two
lines of low-angle sprinklers, only 4 feet apart, straddle an
intensively irrigated raised bed running down the center of the
garden. The sprinklers I use are Naans, a unique Israeli design that
emits very little water and throws at a very low angle (available
from TSC and some garden centers). Their maximum reach is about 18
feet; each sprinkler is about 12 feet from its neighbor. On the
garden plan, the sprinklers are indicated by a circle surrounding an
"X." Readers unfamiliar with sprinkler system design are advised to
study the irrigation chapter in Growing Vegetables West of the
Cascades.

On the far left side of the garden plan is a graphic representation
of the uneven application of water put down by this sprinkler
system. The 4-foot-wide raised bed gets lots of water, uniformly
distributed. Farther away, the amount applied decreases rapidly.
About half as much irrigation lands only 6 feet from the edge of the
raised bed as on the bed itself. Beyond that the amount tapers off
to insignificance. During summer's heat the farthest 6 feet is
barely moistened on top, but no water effectively penetrates the dry
surface. Crops are positioned according to their need for or ability
to benefit from supplementation. For convenient description I've
numbered those rows.


The Raised Bed

Crops demanding the most water are grown on the raised bed. These
include a succession of lettuce plantings designed to fill the
summer salad bowl, summer spinach, spring kohlrabi, my celery patch,
scallions, Chinese cabbages, radishes, and various nursery beds that
start overwintered crops for transplanting later. Perhaps the bed
seems too large just for salad greens. But one entire meal every day
consists largely of fresh, raw, high-protein green leaves; during
summer, looseleaf or semiheading lettuce is our salad item of
choice. And our individual salad bowls are larger than most families
of six might consider adequate to serve all of them together.

If water were severely rationed I could irrigate the raised bed with
hose and nozzle and dry garden the rest, but as it is, rows 1, 2, 7,
and 8 do get significant but lesser amounts from the sprinklers.
Most of the rows hold a single plant family needing similar
fertilization and handling or, for convenience, that are sown at the
same time.


Row 1

The row's center is about 3 feet from the edge of the raised bed. In
March I sow my very first salad greens down half this row--mostly
assorted leaf lettuce plus some spinach--and six closely spaced
early Seneca Hybrid zucchini plants. The greens are all cut by
mid-June; by mid-July my better-quality Yellow Crookneck squash come
on, so I pull the zucchini. Then I till that entire row,
refertilize, and sow half to rutabagas. The nursery bed of leek
seedlings has gotten large enough to transplant at this time, too.
These go into a trench dug into the other half of the row. The leeks
and rutabagas could be reasonably productive located farther from
the sprinklers, but no vegetables benefit more from abundant water
or are more important to a self-sufficient kitchen. Rutabagas break
the winter monotony of potatoes; leeks vitally improve winter
salads, and leeky soups are a household staple from November through
March.


Row 2: Semi-Drought Tolerant Brassicas

Row 2 gets about half the irrigation of row 1 and about one-third as
much as the raised bed, and so is wider, to give the roots more
room. One-third of the row grows savoy cabbage, the rest, Brussels
sprouts. These brassicas are spaced 4 feet apart and by summer's end
the lusty sprouts form a solid hedge 4 feet tall.


Row 3: Kale

Row 3 grows 125 feet of various kales sown in April. There's just
enough overspray to keep the plants from getting gnarly. I prefer
kale to not get very stunted, if only for aesthetics: on my soil,
one vanity fertigation about mid-July keeps this row looking
impressive all summer. Other gardens with poorer soil might need
more support. This much kale may seem an enormous oversupply, but
between salads and steaming greens with potatoes we manage to eat
almost all the tender small leaves it grows during winter.


Row 4: Root Crops

Mostly carrots, a few beets. No irrigation, no fertigation, none
needed. One hundred carrots weighing in at around 5 pounds each and
20-some beets of equal magnitude make our year's supply for salads,
soups, and a little juicing.


Row 5: Dry-Gardened Salads

This row holds a few crowns of French sorrel, a few feet of parsley.
Over a dozen giant kohlrabi are spring sown, but over half the row
grows endive. I give this row absolutely no water. Again, when
contemplating the amount of space it takes, keep in mind that this
endive and kohlrabi must help fill our salad bowls from October
through March.


Row 6: Peas, Overwintered Cauliflower, and All Solanaceae

Half the row grows early bush peas. Without overhead irrigation to
bother them, unpicked pods form seed that sprouts excellently the
next year. This half of the row is rotary tilled and fertilized
again after the pea vines come out. Then it stays bare through July
while capillarity somewhat recharges the soil. About August 1, I wet
the row's surface down with hose and fan nozzle and sow overwintered
cauliflower seed. To keep the cauliflower from stunting I must
lightly hand sprinkle the row's center twice weekly through late
September. Were water more restricted I could start my cauliflower
seedlings in a nursery bed and transplant them here in October.

The other half is home to the Solanaceae: tomato, pepper, and
eggplant. I give this row a little extra width because pea vines
run, and I fertigate my Solanaceae, preferring sprawly tomato
varieties that may cover an 8-foot-diameter circle. There's also a
couple of extra bare feet along the outside because the neighboring
grasses will deplete soil moisture along the edge of the garden.


Row 7: Water-Demanding Brassicas

Moving away from irrigation on the other side of the raised bed, I
grow a succession of hybrid broccoli varieties and late fall
cauliflower. The broccoli is sown several times, 20 row-feet each
sowing, done about April 15, June 1, and July 15. The late
cauliflower goes in about July 1. If necessary I could use much of
this row for quick crops that would be harvested before I wanted to
sow broccoli or cauliflower, but I don't need more room. The first
sowings of broccoli are pulled out early enough to permit succession
sowings of arugula or other late salad greens.


Row 8: The Trellis

Here I erect a 125-foot-long, 6-foot-tall net trellis for gourmet
delicacies like pole peas and pole beans. The bean vines block
almost all water that would to on beyond it and so this row gets
more irrigation than it otherwise might. The peas are harvested
early enough to permit a succession sowing of Purple Sprouting
broccoli in mid-July. Purple Sprouting needs a bit of sprinkling to
germinate in the heat of midsummer, but, being as vigorous as kale,
once up, it grows adequately on the overspray from the raised bed.
The beans would be overwhelmingly abundant if all were sown at one
time, so I plant them in two stages about three weeks apart. Still,
a great many beans go unpicked. These are allowed to form seed, are
harvested before they quite dry, and crisp under cover away from the
sprinklers. We get enough seed from this row for planting next year,
plus all the dry beans we care to eat during winter. Dry beans are
hard to digest and as we age we eat fewer and fewer of them. In
previous years I've grown entire rows of dry legume seeds at the
garden's edge.


Row 9: Cucurbits

This row is so wide because here are grown all the spreading
cucurbits. The pole beans in row 8 tend to prevent overspray; this
dryness is especially beneficial to humidity-sensitive melons,
serendipitously reducing their susceptability to powdery mildew
diseases. All cucurbits are fertigated every three weeks. The squash
will have fallen apart by the end of September, melons are pulled
out by mid-September. The area is then tilled and fertilized, making
space to transplant overwintered spring cabbages, other overwintered
brassicas, and winter scallions in October. These transplants are
dug from nurseries on the irrigated raised bed. I could also set
cold frames here and force tender salad greens all winter.


Row 10: Unirrigated Potatoes

This single long row satisfies a potato-loving household all winter.
The quality of these dry-gardened tubers is so high that my wife
complains if she must buy a few new potatoes from the supermarket
after our supplies have become so sprouty and/or shriveled that
they're not tasty any longer.




Chapter 7

The Backyard


Water-Wise Gardener

I am an unusually fortunate gardener. After seven years of
struggling on one of the poorest growing sites in this region we now
live on 16 acres of mostly excellent, deep soil, on the floor of a
beautiful, coastal Oregon valley. My house and gardens are perched
safely above the 100-year flood line, there's a big, reliable well,
and if I ever want more than 20 gallons per minute in midsummer,
there's the virtually unlimited Umpqua River to draw from. Much like
a master skeet shooter who uses a .410 to make the sport more
interesting, I have chosen to dry garden.

Few are this lucky. These days the majority of North Americans live
an urban struggle. Their houses are as often perched on steep,
thinly soiled hills or gooey, difficult clay as on a tiny fragment
of what was once prime farmland. And never does the municipal
gardener have one vital liberty I do: to choose which one-sixth of
an acre in his 14-acre "back yard" he'll garden on this year.

I was a suburban backyard gardener for five years before deciding to
homestead. I've frequently recalled this experience while learning
to dry garden. What follows in this chapter are some strategies to
guide the urban in becoming more water-wise.


Water Conservation Is the Most Important First Step

After it rains or after sprinkler irrigation, water evaporates from
the surface until a desiccated earth mulch develops. Frequent light
watering increases this type of loss. Where lettuce, radishes, and
other shallow-rooting vegetables are growing, perhaps it is best to
accept this loss or spread a thin mulch to reduce it. But most
vegetables can feed deeper, so if wetting the surface can be
avoided, a lot of water can be saved. Even sprinkling longer and
less frequently helps accomplish that. Half the reason that drip
systems are more efficient is that the surface isn't dampened and
virtually all water goes deep into the earth. The other half is that
they avoiding evaporation that occurs while water sprays through the
air between the nozzle and the soil. Sprinkling at night or early in
the morning, when there is little or no wind, prevents almost all of
this type of loss.

To use drip irrigation it is not necessary to invest in pipes,
emitters, filters, pressure regulators, and so forth. I've already
explained how recycled plastic buckets or other large containers can
be improvised into very effective drip emitters. Besides, drip tube
systems are not trouble free: having the beds covered with fragile
pipes makes hoeing dicey, while every emitter must be periodically
checked against blockage.

When using any type of drip system it is especially important to
relate the amount of water applied to the depth of the soil to the
crops, root development. There's no sense adding more water than the
earth can hold. Calculating the optimum amount of water to apply
from a drip system requires applying substantial, practical
intelligence to evaluating the following factors: soil water-holding
capacity and accessible depth; how deep the root systems have
developed; how broadly the water spreads out below each emitter
(dispersion); rate of loss due to transpiration. All but one of
these factors--dispersion--are adequately discussed elsewhere in
_Gardening Without Irrigation._

A drip emitter on sandy soil moistens the earth nearly straight down
with little lateral dispersion; 1 foot below the surface the wet
area might only be 1 foot in diameter. Conversely, when you drip
moisture into a clay soil, though the surface may seem dry, 18
inches away from the emitter and just 3 inches down the earth may
become saturated with water, while a few inches deeper, significant
dispersion may reach out nearly 24 inches. On sandy soil, emitters
on 12-inch centers are hardly close enough together, while on clay,
30-or even 36-inch centers are sufficient.

Another important bit of data to enter into your arithmetic: 1 cubic
foot of water equals about 5 gallons. A 12-inch-diameter circle
equals 0.75 square feet (A = Pi x Radius squared), so 1 cubic foot
of water (5 gallons) dispersed from a single emitter will add
roughly 16 inches of moisture to sandy soil, greatly overwatering a
medium that can hold only an inch or so of available water per foot.
On heavy clay, a single emitter may wet a 4-foot-diameter circle, on
loams, anywhere in between, 5 gallons will cover a 4-foot-diameter
circle about 1 inch deep. So on deep, clay soil, 10 or even 15
gallons per application may be in order. What is the texture of your
soil, its water-holding capacity, and the dispersion of a drip into
it? Probably, it is somewhere in between sand and clay.

I can't specify what is optimum in any particular situation. Each
gardener must consider his own unique factors and make his own
estimation. All I can do is stress again that the essence of
water-wise gardening is water conservation.


Optimizing Space: Planning the Water-Wise Backyard Garden

Intensive gardening is a strategy holding that yield per square foot
is the supreme goal; it succeeds by optimizing as many growth
factors as possible. So a raised bed is loosened very deeply without
concern for the amount of labor, while fertility and moisture are
supplied virtually without limit. Intensive gardening makes sense
when land is very costly and the worth of the food grown is judged
against organic produce at retail--and when water and nutrients are
inexpensive and/or available in unlimited amounts.

When water use is reduced, yield inevitably drops proportionately.
The backyard water-wise gardener, then, must logically ask which
vegetable species will give him enough food or more economic value
with limited space and water. Taking maritime Northwest rainfall
patterns into consideration, here's my best estimation:


Water-Wise Efficiency of Vegetable Crops

(in terms of backyard usage of space and moisture)


EFFICIENT ENOUGH


Early spring-sown crops: peas, broccoli, lettuce, radishes, savoy
cabbage, kohlrabi

Overwintered crops: onions, broccoli cauliflower,
cabbage, favas beans

Endive Kale

Garden sorrel

Indeterminate tomatoes

Giant kohlrabi

Parsley--leaf and root

heirloom summer squash (sprawly)

Pole beans

Herbs: marjoram, thyme, dill, cilantro, fennel, oregano

Root crops: carrots, beets, parsnips


MARGINAL


Brussels sprouts (late)

Potatoes

Determinate tomatoes

Rutabagas

Eggplant

Leeks

Leeks

Savoy cabbage (late)

Peppers, small fruited


INEFFICIENT


Beans, bush snap

Peppers, bell

Broccoli, summer

Radishes

Cauliflower

Scallions, bulb onions

Celery

Sweet corn

Lettuce

Turnips

Have fun planning your own water-wise garden!





More Reading

About the Interlibrary Loan Service


Agricultural books, especially older ones, are not usually available
at local libraries. But most municipal libraries and all
universities offer access to an on-line database listing the
holdings of other cooperating libraries throughout the United
States. Almost any book published in this century will be promptly
mailed to the requesting library. Anyone who is serious about
learning by reading should discover how easy and inexpensive (or
free) it is to use the Interlibrary Loan Service.

Carter, Vernon Gill, and Tom, Dale. _Topsoil and Civilization._

Norman, Okla.: University of Oklahoma Press, 1974.

The history of civilization's destruction of one ecosystem after
another by plowing and deforestation, and its grave implications for
our country's long-term survival.

Cleveland, David A., and Daniela Soleri. _Food from Dryland Gardens:
An Ecological, Nutritional and Social Approach to Small-Scale
Household Food Production._ Tucson: Center for People, Food and
Environment, 1991.

World-conscious survey of low-tech food production in semiarid
regions.

Faulkner, Edward H. _Plowman's Folly._ Norman, Okla.: University of
Oklahoma Press, 1943.

This book created quite a controversy in the 1940s. Faulkner
stresses the vital importance of capillarity. He explains how
conventional plowing stops this moisture flow.

Foth, Henry D. _Fundamentals of Soil Science._ Eighth Edition. New
York: John Wylie & Sons, 1990.

A thorough yet readable basic soil science text at a level
comfortable for university non-science majors.

Hamaker, John. D. _The Survival of Civilization._ Annotated by
Donald A. Weaver. Michigan/California: Hamaker-Weaver Publishers,
1982.

Hamaker contradicts our current preoccupation with global warming
and makes a believable case that a new epoch of planetary glaciation
is coming, caused by an increase in greenhouse gas. The book is also
a guide to soil enrichment with rock powders.

Nabhan, Gary. _The Desert Smells like Rain: A Naturalist in Papago
Indian Country._ San Francisco: North Point Press, 1962.

Describes regionally useful Native American dry-gardening techniques

Russell, Sir E. John. _Soil Conditions and Plant Growth._ Eighth
Edition. New York: Longmans, Green & Co., 1950.

Probably the finest, most human soil science text ever written.
Russell avoids unnecessary mathematics and obscure terminology. I do
not recommend the recent in-print edition, revised and enlarged by a
committee.

Smith, J. Russell. Tree Crops: a Permanent Agriculture. New York:
Harcourt, Brace and Company, 1929.

Smith's visionary solution to upland erosion is growing unirrigated
tree crops that produce cereal-like foods and nuts. Should sit on
the "family bible shelf" of every permaculturalist.

Solomon, Stephen J. _Growing Vegetables West of the Cascades._
Seattle: Sasquatch Books, 1989.

The complete regional gardening textbook.

-------------------------.  _Backyard Composting._ Portland, Ore.:
George van Patten Publishing, 1992.

Especially useful for its unique discussion of the overuse of
compost and a nonideological approach to raising the most nutritious
food possible.

Stout, Ruth. _Gardening Without Work for the Aging, the Busy and the
Indolent._ Old Greenwich, Conn.: Devin-Adair, 1961.

Stout presents the original thesis of permanent mulching.

Turner, Frank Newman. _Fertility, Pastures and Cover Crops Based on
Nature's Own Balanced Organic Pasture Feeds._ San Diego: Rateaver,
1975. Reprinted from the 1955 Faber and Faber, edition.

Organic farming using long rotations, including deeply rooted green
manures developed to a high art. Turner maintained a productive
organic dairy farm using subsoiling and long rotations involving
tilled crops and semipermanent grass/herb mixtures.

ven der Leeden, Frits, Fred L. Troise, and David K. Todd. _The Water
Encyclopedia, Second Edition._ Chelsea, Mich.: Lewis Publishers,
1990.

Reference data concerning every possible aspect of water.

Weaver, John E., and William E. Bruner. _Root Development of
Vegetable Crops._ New York: McGraw-Hill, 1927.

Contains very interesting drawings showing the amazing depth and
extent that vegetable roots are capable of in favorable soil.

Widtsoe, John A. _Dry Farming: A System of Agriculture for Countries
Under Low Rainfall._ New York: The Macmillan Company, 1920.

The best single review ever made of the possibilities of dry farming
and dry gardening, sagely discussing the scientific basis behind the
techniques. The quality of Widtsoe's understanding proves that newer
is not necessarily better.