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  THEORY AND PRACTICE,
  APPLIED TO THE
  CULTIVATION
  OF
  THE CUCUMBER,
  IN THE
  WINTER SEASON:

  TO WHICH IS ADDED,
  A CHAPTER ON MELONS:

  BY THOMAS MOORE,
  MEMBER OF THE BOTANICAL SOCIETY OF LONDON.

  SECOND EDITION,

  WITH AN APPENDIX, CONTAINING REMARKS ON HEATING
  AERATING, AND COVERING FORCING HOUSES; ON
  TRANSPLANTING, AND THE USE OF TURF POTS; ON
  WATERING; ON ATMOSPHERIC HUMIDITY, &c., &c.

  LONDON:
  RICHARD GROOMBRIDGE AND SONS,
  5 PATERNOSTER ROW.

  MDCCCXLVII.



  LONDON:
  PRINTED BY DAVID M. AIED
  JAMES ST., COVENT GARDEN.




PREFACE TO THE FIRST EDITION.


This little treatise is intended as an inducement to young Gardeners
especially, to seek for the reasons on which the operations of their daily
practice are founded, and by which they are regulated. This announcement
is here made, in order to prevent any reader from supposing that the
author has unduly estimated the opinions of those who have benefited by a
long course of application and experience. As, however, there can be no
doubt that there is much to be learned, so is there but little question
that there is also much to be unlearned, in the present state of the
Science of Horticulture; and these pages are offered without hesitation,
as a mite among the accumulating mass of available information on
gardening subjects; and in the hope that some amongst those who are
seeking to extend their knowledge, may at least be stimulated by their
perusal, if they are not otherwise directly benefited.

The great truths which it is the object of this treatise to impress, are
these: that the ultimate success of gardening operations does not depend
on the performance of any part of them, at a particular time, or in a
particular or even superior manner, but rather upon the supplying, in a
natural manner, as far as possible, _all the conditions_ which are
necessary to the nutrition and perpetuation of plants; and, that it is
within the open pathway of Science, and not the bye-ways of empiricism,
that the finger-post of direction should be sought.

Royal Botanic Garden, Regent's Park,

March 2nd, 1844.




TO THE SECOND EDITION.


In the present edition, it has been thought best to preserve the original
text exactly as it appeared in the first edition. The new matter will be
found in the Appendix.

The author may take this opportunity of returning his thanks to those who
have noticed and commended the former edition, and of expressing a hope
that the present will receive an equal share of favour.

Camden Town, Aug. 1, 1847.




CONTENTS.


  CHAP. I.                                                          PAGE

  Botanical name, and affinities of the Cucumber--properties--
  foreign names--improvements in cultivation                           9


  CHAP. II.

  Structures--dung beds--brick pits--forcing houses--gutter
  system of heating--the tank system--bottom heat--description
  of Cucumber house--aspect--position--angle--covering                11


  CHAP. III.

  Propagation by cuttings--early fruitfulness--preservation of
  varieties--layers--objections to cuttings and layers--seeds--
  disadvantages--progressive growth--seed sowing                      23


  CHAP. IV.

  General principles of culture--importance of light--pruning
  and training                                                        31


  CHAP. V.

  Composition of the soil--heath soil--leaf mould--preparation
  of soil--charcoal--manures--liquid manures                          36


  CHAP. VI.

  Application of water to the soil--special conditions--
  atmospheric moisture--insects--mildew--canker--mode of watering     42


  CHAP. VII.

  Regulation of temperature--principles to be kept in view--day
  and night temperature--deductions                                   46


  CHAP. VIII.

  Admission of air--effect of cold air on tender plants--
  deterioration--evils resulting from unguarded atmospheric
  changes--mode of admitting air--atmospheric influence on
  vegetation--nitrogen--carbon                                        50


  CHAP. IX.

  Growth of Persian Melons in summer--peculiarities of
  treatment--soil--watering--solar heat--light                        56


  CHAP. X.

  Conclusion                                                          59




TREATISE.




CHAP. I.

INTRODUCTORY REMARKS.


The Cucumber, _Cucumis sativa_, is supposed to be a native of the East
Indies; but like many other of our culinary plants, the real stations
which it naturally has occupied, are involved in obscurity: in habit it is
a trailing herb, with thick fleshy stems, broadly palmate leaves, and
yellow axillary monæcious flowers. In the natural arrangement of the
vegetable kingdom, the genus of which it forms part, ranks in the first
grand class, _Vasculares_, or those plants which are furnished with
vessels, and woody fibre; in the sub-class _Calycifloræ_, or those in
which the stamens are perigynous; and in the order _Cucurbitaceæ_, or that
group, of which the genus _Cucurbita_, or Gourd family is the type.

The affinities of this order, are chiefly with _Loasaceæ_, and
_Onagraceæ_; with the former it agrees in its inferior unilocular fruit,
having a parietal placentæ, and with the latter, in its definite
perigynous stamens, single style, and exalbuminous seeds. It has also some
affinity with _Passifloraceæ_, and _Papayaceæ_, in the nature of the
fruit, and with _Aristolochiaceæ_, in its twining habit, and inferior
ovarium. M. Auguste St. Hiliare, also regards it as being related to
_Campanulaceæ_, in the perigynous insertion of the stamens, the single
style with several stigmas, the inferior ovarium, and in the quinary
division of the floral envelope, in connection with the ternary division
of the fruit.

The properties of the plants comprised in this natural family, are not
numerous; a bitter laxative quality pervades many of them, a familiar
example of which is the resinous substance called Colycinthine, the
production of the Colocynth gourd, in which the active purgative principle
is concentrated, rendering it drastic, and irritating. Among our native
plants the roots of _Bryonia dioica_, in common with the perennial roots
of all the plants in the order, possess these purgative properties. On the
other hand, the seeds are sweet, yielding an abundant supply of oil; and
it may be worthy of remark, that they never partake of the properties of
the pulp with which they are surrounded in the fruit.

The Cucumber does not possess the properties common to the order, in very
powerful degree; its fruit is however too cold for many persons, causing
flatulency, diarrhoea, and even cholera; by others, it may be eaten with
avidity, without producing any injurious effects.

The names by which the Cucumber is recognised by the Hindoos, are
_Ketimon_, and _Timou_. In the French, it is called _Concombre_; in the
German, _Gurke_; and in the Italian, _Citriuolo_. As a cultivated plant,
it is of nearly equal antiquity with the Vine; being mentioned by the
writer of the Pentateuch, as being cultivated extensively in Egypt, above
3000 years since.

The cultivation of this plant, and the production of fine fruit at an
early season, is an object of emulation among gardeners of the present
day; and from this cause, many important improvements in the mode of its
cultivation have been effected. The vast increase of means, arising from
an acquaintance with powerful agents, formerly unknown, which are
available by the present and rising races of gardeners, enable them to
secure the same important results which cost their predecessors much both
of labour and anxiety, with a comparatively small amount of the former,
and a degree of certainty at which they could never arrive. The agents
which an enlightened age has brought under controul, are indeed powerful
engines, which require much skill in their adaptation and management; but
the knowledge necessary to effect this, is so firmly and inseparably
connected with the first principles of cultivation, that an acquaintance
with these, will at all times supply a safe and unerring guide to their
application.

It is to assist the young gardener in this application of principles, to
the growth of the Cucumber in the winter season, that these pages are
designed; and of those who may differ from the opinions which are here
expressed, it is only required that they should receive a calm and
deliberate consideration--a consideration unbiassed by prejudice, and
unmixed with any of that feverish excitement after novelties, which with
gardeners, as well as with all other classes of society, is becoming far
too prevalent, and intense.




CHAP. II.

ON THE STRUCTURES ADAPTED FOR THE GROWTH OF CUCUMBERS.


I will preface the following remarks on the structures adapted for the
growth of Cucumbers, by stating, that a forcing house, a pit, and a common
frame, present the means of bringing this fruit to its perfection,
equally, one with the other, provided that a course of cultivation
suitable to the structure, is followed out; the comparative merits of
each, depend not so much on the nature of the results which may be
obtained by adopting them, as on the facilities they afford for the
attainment of those results.

The use of the common frame, and the ordinary hotbed of fermenting manure,
nevertheless involves these difficulties:--the fermentation is liable to
become excessive, and that in a very rapid manner, and also to decline as
rapidly; the heat, when declining, cannot be speedily restored in
unpropitious weather; it is materially checked in its action, by that
particular state of the weather, which renders its efficient action most
essential; it involves almost an infinitude of labour; and after all, it
is uncertain in its action: when such difficulties as these, are overcome,
Cucumbers can be grown to perfection, on dung beds, assisted by the common
garden frame and sash.

The brick pit, when heated by fermenting manure, presents difficulties of
the same nature with the preceeding, though in a less powerful degree: but
when these structures are heated by means of hot water, in any of its
various modes of application, there need be no irregularity, nor
uncertainty in its action; because the supply of the elements of vegetable
developement, and of the agents by whose aid they are applied, may, to a
very great extent, go on uninterruptedly.

A forcing house, whilst it secures all the advantages which are presented
by a pit, combines with these, some important points which are peculiarly
its own: by adopting a pit, we provide a structure of which Cucumbers
manifest their approval, by thriving equally as well as in their more
ancient location on a dung bed; but further than this, a pit enables us to
dispense with much of the labour, and all the filth, and the uncertainty
which are consequent on the use of fermenting manure as a means of keeping
up the temperature in which they are grown. In a small forcing house,
besides these advantages being secured, all the operations of care and
culture, can be performed just when they become necessary, without
exposing the tender foliage of plants which have been submitted to an
artificially elevated temperature, to the chilling influence of cold air,
which is admitted whenever the sashes of an ordinary frame or of a pit,
are opened, in order to bestow these necessary attentions. It may be urged
that a dung bed has still the advantage, on the ground of economy; but
when a fair calculation is made of labour and loss or anxiety on the one
hand, and of duration on the other, such an assumption, will be quite
untenable. Neatness, convenience, certainty, and economy, are the
principal points of advantage which are gained by the adoption of pits
heated by means of hot water, over those of a structure, depending for its
supply of heat, on the aid of fermenting masses; whilst the attainment of
a still greater degree both of convenience, and of certainty, which may be
secured by cultivation in forcing houses, point out at once the advantages
which render such houses, preferable to pits.

The application of the gutter system of heating, was not long since
thought to be an improvement of great importance, and there can be no
question but that it affords a means of regulating the moisture of the
atmosphere of hothouses, in conjunction with the temperature, which prior
to its introduction had not been attained; and as such, it is worthy of
extensive adoption: it requires however some judgement in its adaptation
to particular structures, and to render, it suitable, to effect any
particular object for which it may be employed.

The tank system as a means of applying bottom heat, employed either in
conjunction with the gutters, or with ordinary piping, to supply heat to
the atmosphere, is the most important advance which has hitherto been made
towards supplying the wants of those plants, which require such peculiar
aid; and with reference to the Cucumber, it may be regarded as furnishing
a new era in its cultivation.

The importance of bottom heat in the culture of tender plants, has always
been well known by its practical effects. The mean temperature of the
soil, at a slight distance below the surface, is universally above that of
the superincumbent air; and consequently some degree of bottom heat is
always supplied to plants, in a state of nature. Naturally, by means of
subterraneous heat, and also by the absorption of the sun's rays during
the time they are forcibly directed towards the earth, it possesses the
means whereby any material degree of cold at the roots of plants is
prevented; and when the soil is acted on by the unveiled sun of an eastern
sky, we cannot but feel certain, that even a considerable amount of heat
must be experienced: hence arises the importance of taking advantage of
every ray of sun which our climate affords, when the culture of the
Cucumber, or of any native of warmer latitudes, is attempted out of doors
in this country; and also of using every possibly available means of
increasing rather than diminishing the temperature of the soil: and hence
too, in forcing not only the Cucumber, but also every other plant which
requires to be submitted to a confined atmosphere, and an elevated
temperature, arises the necessity of providing such a degree of warmth at
the root, as may tend to keep its vital powers in a vigorous state of
action; it will effect this, by acting in conjunction with moisture, as a
solvent of the food which is primarily contained in the soil in a solid
form, but can only be taken up by the capillary action of the spongioles
of the roots, when converted into a fluid state. The science of Chemistry
has taught us that the ingredients composing the soil, act on, and
dissolve, and combine with each other in various ways, sometimes being
simply dissolved and held in solution, and at other times, entering into
new combinations, and forming new compounds; but in all cases, the natural
agents, heat and moisture, are necessary to produce these results, and to
present to the tender roots of plants, food so duly prepared, as to be
fit for their assimilation. Warmth in the soil, acts beneficially also, by
preventing the sudden or undue interruption of the excitability of plants
growing in it, which would be likely to result from the lowering of the
temperature of the plants by evaporation, were it not for the action of
the antagonist force, existing in and exercised by the heated soil, which
heat, is communicated to, and absorbed by the plants.

It may be regarded as an established and universal rule, that all plants
require the soil, and the atmosphere in which they are cultivated, to
correspond with the natural circumstances under which they flourish; and
as it has been repeatedly ascertained that the soil is naturally a degree
or two above the temperature of the atmosphere, we have certain and
unerring data for the application of bottom heat, and no more powerful
evidence than this can be desired, to condemn at once the application of a
_very powerful degree of heat_, at the roots of plants.

The importance of bottom heat in the culture of tender plants, being a
practical fact established beyond question, another consideration arises
as to the best means of producing it, and of regulating its application.
Various substances and materials have been submitted to a process of
fermentation, and so employed to effect it: stable manure, tanner's bark,
and the leaves of trees, are among the principal of these materials, and
either of them will supply just what the plants require, as truly as these
wants can be supplied by any other means; but from their very nature, they
are violent, and fluctuating, and ephemeral in their action, and setting
aside the labour which the employment of them necessarily involves, we
have in these particulars, the special points in which the tank system of
applying bottom heat far excels them: it is uniform, and constant, in its
action; there need be no apprehension of the soil becoming overheated, for
the source whence it derives its warmth ought never to boil; neither need
there be any fear of its decline, or of a want of power, for when once
thoroughly heated, a body of water will part with it in such a manner,
that a very little attention to the fire, and a very little expenditure of
fuel, will maintain its temperature for an almost incredible length of
time; and as to power, it never should for a moment form a question,
because a powerful degree of bottom heat ought never to be applied: a
close attention for one or two hours during the twenty four which form a
day, will maintain any apparatus in an effective state of action, if it is
properly erected. How different is this, to what has been in days now
past! when in rigorous weather, with the heat of his dung bed declining,
the cultivator knew that at the peril of his crop, he scarcely dared to
attempt to revive it, without involving a more serious because an
accelerated evil; at any rate, if at an immense sacrifice of labour, his
dung casings were replenished piece by piece, he knew too well, that often
many days would elapse, before their action would be efficient and
satisfactory, unless indeed an unlimited supply of materials, were in a
constant state of preparation. By means of the tank, a fire could be
lighted up, and the required effect produced in as many hours, as days
would have been formerly required.

What has been already advanced, tends to the conclusion, that small
forcing houses are preferable, and in the end more economical than pits
and dung beds; and that the tank as a means of supplying bottom heat, is
preferable to the use of fermenting materials; _because the results in
each case, are more perfectly under controul_. Whilst on this part of the
subject, I may be allowed to mention an error which is somewhat prevalent:
We frequently hear of the humid nature of the heat given off by hot water
pipes, in comparison with that derived from such appliances, as a flue; it
is not unfrequently asserted, that the heat thus derived is so moist, so
genial, so peculiarly adapted to plants: there can be no doubt but that
the heat thus obtained is infinitely preferable to that obtained through
the medium of flues, generally speaking; but its superiority consists
rather in its purity, its freeness from noxious gasses, than in its
possessing a greater degree of moisture. Heat--that is--caloric, is the
same, whatever may be the medium by which it may be conducted; and in the
case of hot water pipes, they give off that which has been conducted to
them by the water, directly from the fire, the water acting as a mere
conductor; it is difficult to conceive any thing more thoroughly devoid of
moisture than the heat thus communicated: let any one who doubts this,
place a damp cloth on a series of hot water pipes when in action, and the
result will soon work conviction. With these general remarks, I will
proceed to describe the kind of structure which I regard as being
peculiarly adapted to the growth of Cucumbers; and notice some of the
conditions which it is necessary to keep in view: the engraving on the
next page, represents such a structure.

The aspect of the Cucumber house, should be nearly S.S.E; or in other
words--it should be so regulated between the points south and east, that
whilst the rays of the sun will be admitted as fully and as early as
possible in the morning, there may be no obstruction offered to their more
powerful action as that body approaches the meridian. In the growth of all
tender plants, light and sun heat are required during the winter months as
well as in summer, and there can be no greater error as regards the
erection of structures devoted to such purposes, than to provide for their
admitting the direct rays of the sun in the earlier part of the day, at
the expense of refracting and thereby weakening, to a greater degree than
is really unavoidable, the power of the noon-tide rays of that
invigorating and life-sustaining agent: during the summer months, though
plants then require both light and sun heat, yet the case is different;
the sun's rays have then much greater power, and it is found that their
influence is sufficient, without at all times admitting them directly on
the plants growing in these artificial atmospheres.


[Illustration]


The position of the Cucumber house, with reference to the ground line,
must be determined by local circumstances; if the situation and sub-soil
be dry, it may be carried below the surface in the manner represented in
the annexed engraving, of which (_a_) is the ground line, (_b_) the
pathway, and (_c_) the lowest point excavated: the same course may be
adopted if the soil, though not naturally so dry as this, can be rendered
so by thorough drainage; but when the ground does not admit of perfect
drainage, the structure must be sufficiently elevated to avoid the risk of
injury from the dampness of the locality.

The angle of elevation is not, as it is sometimes asserted to be, a point
of indifference, though mathematical accuracy is certainly by no means
required: in the annexed engraving, the angle of the roof is about 55°,
this provides for the admission of the sun's rays in the winter months,
when his position is comparatively low in the horizon, to a much greater
extent than could take place if a more ordinary slope were adopted. A
still more elevated pitch would doubtless effect this object in a still
more perfect manner; but would not be equally applicable to the
requirements from a permanent structure, which would be wanted for summer
as well as winter use.

A reference to the sketch, will at once shew the general nature of the
internal arrangements. There should be a tank (_d_) supported by brick
piers (_p_) in which a circulation of heated water would supply a genial
warmth to the soil above, and to the roots of the plants growing in the
soil; this tank should be heated by a small boiler, conveniently placed
with reference to adjacent arrangements; a series of iron pipes (_e_)
attached to the same boiler, would supply the requisite heat to the
atmosphere. It may perhaps be thought that the application of the gutter
system of heating would in this case be preferable; but as there would be
a perfect command of moisture, as will be explained further on, it is
desirable to have dry heat also, under controul, and this can be better
effected by means of the pipes than by adopting the gutter plan of
heating. I cannot in this place forbear protesting against the limited
surface of piping generally employed in heating plant structures; what is
thought to be just enough to maintain a given temperature, is usually
after minute calculation, the quantity which is made use of, and the
consequence is, that under adverse circumstances, the apparatus is
necessarily worked at its highest pitch; and I believe that the
application of heat in this form, whether it be by means of an hot water
apparatus, or by a common flue, is most inimical to the plants submitted
thereto. The admission of air, is a point which as far as I am aware, has
never been effected in the manner represented in the sketch: it would be
thus effected;--a series of apertures (_f_) should be provided at
intervals along the front wall, which would externally be closed by small
sliding shutters, and would communicate internally with a chamber (_g_)
formed between the front wall and the side of the tank; this chamber would
also communicate, by a series of openings, (_h_) with the interior space
above the water in the tank, and from this space, through the covering of
the tank, tubes (_m_), also placed at intervals, would be carried up
through the soil, close to the side of the wall; these tubes should be
furnished with caps or valves, so as so admit of the communication being
stopped at any time. In applying this to the admission of air, we must not
loose sight of a series of ventilators, (_i_), placed in the back wall of
the house, which are of precisely the same nature and construction as the
apertures (_f_), already spoken of. I shall have occasion hereafter, to
notice the admission of air, but it will be well in this place, to explain
the action of the plan proposed for that purpose: when it is judged that a
change of the internal volume of air is requisite, the ventilators (_i_)
are to be opened, which admits of a portion of the rarified air to pass
off; the ventilators (_f_) are also to be opened, and by means of the
action of these ventilators on each other, a portion of external air is
taken in; this enters the chamber (_g_), which is warmed by its contiguity
to the tank, and here becomes partially rarified, and rises to the top of
the chamber; the apertures (_h_) admit it to the interior of the tank,
where it becomes not only thoroughly warmed, but also imbibes a degree of
moisture proportionate to the degree in which it becomes heated, and
thence it enters the house by the tubes or shafts already spoken of. The
advantages of warming and moistening the air thus admitted, are very
important ones; for when either a cold or dry state, of the atmosphere
prevails, its influence is very injurious to plants in these confined
situations: cold raw air, when it comes in contact with the tender foliage
of the plants, has the effect of chilling the sap in its progress through
their tissue, and thus lessening their excitability, when it should be
increased; whilst dry air acts as an incessant drain upon the vegetable
juices, which it abstracts through the stomates and pores of the leaves
and stems. When cold air is admitted to any position where it can unite
with caloric, and not in an equal ratio with moisture, it necessarily
becomes arid, and in that state it eagerly combines with moisture in any
form with which it can come in contact therewith; and consequently if cold
air is admitted to a plant structure, where it can have the means of
combining with heat, faster than with moisture, it would be brought into
this arid state, and would supply its voracious appetite, by abstracting
the juices of the plant. It is a very important question how far this
state of things is connected with many of the diseases as they are called,
to which plants are subject; for my own part, I believe it to have a very
considerable influence in the production of many of them. A shallow bed of
soil (_k_), is all that would be required; for in the winter season, there
is nothing gained by encouraging a very luxuriant and gross state of
growth: the composition of this soil will be noticed hereafter: beneath
it, and resting on the top of the tank, should be placed a layer of coarse
open rubble, not less than six inches in thickness; and among this rubble
by means of tubes (_n_), placed at intervals along the bed, I would
occasionally pour considerable quantities of water, in order to maintain a
due regulation of moisture in, and throughout the soil, among which the
vapour arising from the water would ultimately rise. Beneath the tank a
space (_o_), might be provided, which would serve admirably either for the
cultivation of Mushrooms, or the forcing of Rhubarb, or Sea Kale.
Transverse partitions should be introduced into the bed of soil, so as to
divide the roots of each plant from those of its neighbours: this
arrangement will admit of a complete succession of plants being
maintained, by the removal of those which have become old and debilitated,
and the substitution of young and vigorous ones; and this obstruction of
the roots, will not be injurious, for the Cucumber does not by any means
require to be permitted to extend its roots at random, but will readily
submit itself to any rational regimen, with regard to the area from whence
it is permitted to extract its food. A portion of soil sufficient to
support one or two plants, could by this arrangement be renewed as
occasion might require, and the roots of the contiguous plants would
suffer no injury from the operation. The pathway of the house, should be
paved so as to admit of its being occasionally washed and cleansed.

It will be found to be highly economical in reference to the consumption
of fuel, to provide the structure with the means of being covered at
night. Shutters of light frame-work, covered with any waterproof material,
would be found to answer the purpose admirably; they should be elevated a
few inches from the surface of the glass, and they should be arranged so
as to confine a body of air, which acting as a very slow conductor of
heat, would serve to prevent that incessant drain upon the temperature of
the internal atmosphere, which takes place when the material employed is
in contact with the glass, as well as when coverings are altogether
absent. This would not be the only advantage, for as the covering would
to a great extent prevent the radiation of heat from the internal
atmosphere, so would it also prevent the necessity of the application of
so powerful a degree of fire heat at night; and thus the plants would be
permitted to enjoy that natural season of repose so essential to their
well being, instead of being forced into growth by reason of a high
temperature kept up, solely for the purpose of obviating the external
cold.




CHAP. III.

ON THE PROPAGATION OF THE CUCUMBER.


Cucumbers are propagated by cuttings, by layers, and by seeds; the two
former of these methods being frequently practised by those who have
conveniences to keep their plants growing throughout the year; the latter
being adopted either through choice or necessity, by the majority of
cultivators, or those whose means will not enable them, even if they
desired it, to keep up continually a successional growth.

Propagation by cuttings has many advantages to recommend it, especially
when viewed in connection with the production of winter fruit. The plants
raised by this mode of treatment, in comparison with those raised from
seeds, are less gross and succulent in their nature, and more subdued in
their manner of growth; whether it may be that having mature and perfectly
formed parts, they are enabled to assimilate their food more rapidly, than
young and imperfectly formed plants can do; or whether it is owing to any
difference in the balance between the roots and leaves, which latter
organs, in cuttings, and the former, in seedling plants, may be regarded
as predominant, does not appear quite evident, probably the effect depends
partly on each of these supposed causes. They are moreover, sooner in
arriving at a fruit-bearing state, by reason of a universal natural law,
by which the inflorescence and fructification of a plant becomes more
general and perfect, in proportion as the plant attains proximity to its
perfect developement; which effect, is owing to the more perfect
elaboration and preparation of the materials, which when so prepared,
furnish the means of perfecting the organs of reproduction. For the same
reason, the operation of budding a portion of a seedling fruit tree, on a
matured stem, is practised, in order to accelerate its fruitfulness; which
result generally follows, in consequence of the difference existing in the
nature of the food elaborated by the mature plant, and that deposited by
one in an infant state. Thus it is also, that cuttings of flowering plants
generally, are far sooner in arriving at a blooming state, than seedling
plants of the same species: flowers and fruit being formed only by the aid
of the perfectly elaborated sap; which is taken up into the system, and
assimilated in the plant, in proportion to the number of healthy and
mature leaves, in a full state of action: during the younger stages of
growth, the crude material imbibed from the soil, is only partially
elaborated, and in this state, is only converted into food suitable and
destined to increase the foliaceous organs; but when these latter are in
full and vigorous action, a supply of matter, not increased in quantity,
but enriched in quality, becomes laid up in the store-house and structure
of the plants; and it is by means of this matter, aided by the natural
agents, that the nature of the developement is changed from being simply
that of the organs of nutrition, to that of the more perfect and important
organs of reproduction. Besides the precocity of plants propagated by
cuttings, there is also another advantage resulting from the practice,
and that is the preservation of particularly desirable varieties; the
Cucumber is a plant which readily admits of hybridization, and although
the result of this is sometimes to give rise to superior varieties, yet if
impregnation is permitted to take place promiscuously, the bad qualities
of particular varieties, are as likely to be combined in the succeeding
race, as the good and desirable ones: this renders it important that the
fruit which are preserved for seed, should have been carefully watched and
protected when in blossom, from the reach of insects; which often effect
the requisite union, in consequence of the pollen adhering to their
bodies, and thus being brought into contact with the stigma. I need
scarcely to say, that where only one variety is grown in any particular
structure, the chances of admixture are less numerous.

The manner in which the operation of propagation by cutting is performed,
is very simple: the tops of healthy growing shoots are taken off, at about
two or three joints in length; they are then planted in deep pots, which
are about half filled with light earth, such as decayed vegetable matter,
and then covered by laying a piece of glass on the top of the pot; a
simple and effective protection is thus formed, the sides of the pot
acting as a partial shade, the glass admitting light sufficiently abundant
to secure the action of the leaves, and maintaining a calm and moist
atmosphere: the pots are to be plunged in a gentle bottom heat, and the
cuttings will soon become rooted; after which they may be treated as
established plants.

Propagation by layers, is another method similar to the last, of which it
is a mere modification; and those points which mark the superiority of the
one, are equally applicable in the case of the other. The operation may be
performed in various ways: thus the branches may be layered at once into
the soil, when these are trained close to its surface, and they will thus
grow on with renewed vigour: when required for removal to other positions,
they may be layered into pots of light soil, in doing which, a convenient
branch may be brought down, secured firmly at a joint to the soil, and
slightly covered therewith, when it will soon become rooted: another plan,
is, to suspend in convenient places, pots having large holes beneath;
through these holes, the points of growing shoots are introduced, and the
pots having a little moss in the bottom, are then lightly filled with
vegetable mould: they may also be propagated, by enveloping a joint of a
growing shoot lightly with moss; the moss should be kept continually
moist, and roots will soon be emitted into it, and when enough are
produced, the plant may be detached.

Either of these methods of propagation will secure not only healthy, but
fruitful plants, in a short space of time; and this latter point will be
found to be one of no small advantage. The principal objection which may
be urged against their adoption, is that they necessarily involve a
process of transplantation, which under any circumstances, and however
carefully performed, must be regarded as an evil rather than otherwise. It
may be thought that the _check_ arising from transplantation may do good,
by preventing too great luxuriance of growth, and thereby tending to
accelerate fruitfulness; but even if this result may be apparently
produced by such means, it is surely far more natural to check the plants,
by withholding a portion of food, rather than by mutilating the organs by
which their food is conveyed to them, and then actually placing them in a
position where food is still more abundantly supplied than before. It is
very questionable however, how far what is called a "check" is justifiable
as a means of inducing fructification; for if fructification be the most
perfect state at which a plant can arrive, there does not seem to be much
rationality in adopting any such means as a "check" in bringing about
this perfection of developement. A _check_ applied as a means of
accelerating maturity, can only be regarded as an expedient, rendered
necessary by previous defective treatment.

The most commonly practised as well as the most natural method of
propagation, is by seeds, and this will generally be found to be also the
best method, if the conditions required by its adoption can be properly
carried out. There is however, one decided disadvantage attendant on the
raising of Cucumber plants intended for winter forcing from seeds; and
hence in a great measure arises the apparent superiority of propagating by
extension: the disadvantage consists in the exceedingly succulent and lax
nature of the tissue of the young plants; owing to that natural principle,
by which their increase and extension is most especially provided for
during the infant stages of their existence: the result is, that in
consequence of the deficiency of light and solar heat, which are the grand
agents of vegetable fructification, their sap does not become sufficiently
elaborated, nor their tissue rendered sufficiently solid by assimilation
and deposition of matter, to bring about the developement of floral parts;
the food and moisture imbibed, instead of being sublimated and fully
elaborated, is only partially acted on by the vital and natural agents,
and the result is an increase of growth, but not a developement of
fruit-bearing parts. There is nevertheless, an advantage in raising plants
from seeds, not only as regards the obtaining of improved races, but also
in a cultural point of view. The science of Horticulture, does acknowledge
such a thing as progression, in the developement of plants; the functions
of nutrition necessarily go on prior to those of reproduction or
fructification, the latter being continually dependant on, as well as
being the result of the former: hence we arrive at a conclusion, that _to
supply uninterruptedly_, ALL _the elements which administer to the
nutrition of a plant, is the most rational means of inducing a state of
fruitfulness_. This may at first sight be questioned; cases may readily
enough be quoted, in which food has been bountifully supplied, and the
plants have grown amazingly, but not fruited; if however, food had been
thus supplied, in connexion with a due share of _light_, and an _excess of
heat_ had been avoided, we have natural evidence to prove unquestionably
that fructification would have followed. An abundance of food, a high
temperature, and a deficiency of light, are just the conditions which are
opposed to the developement of the floral organs in plants, and are
inductive of mere barren extension: not that plants grow thus, because
they delight in such a state of things, but because they are thereby
unnaturally excited and compelled to do so, although that growth cannot
under such circumstances, become properly matured; and hence arises the
impossibility of their producing blossoms.

The advantage of raising plants of Cucumbers from seeds, consists in the
facility thus afforded of altogether avoiding transplantation: the roots
of Cucumbers are of a very tender nature, and however carefully they may
be transplanted, they are liable to sustain injury in the removal: by
having recourse to depositing the seeds at once in the soil where they are
intended to grow, this is entirely obviated, and there can be no possible
reason why the conditions necessary to germination should not be as fully
supplied in a hillock of soil, as when a portion of the soil is placed
within a garden pot; this vessel can certainly have no influence in
producing more perfect or healthy germination, whilst the mutilation of
even the most careful act of transplantation, may tend to check the future
developement of the plant.

It may be, however, that circumstances prevent the sowing of the seeds at
once in their ultimate position, and in such cases, they may be sown
singly in pots partly filled with decayed vegetable mould, plunged in a
milk-warm bottom heat. The temperature both of the soil and atmosphere
during this period, should not be high, but such as to permit the plants
to push gradually forth from their dormitory, and assume by a natural
process, the functions of active vitality. In order to maintain them in
vigour of constitution, they should be exposed as much as possible to
light; and that, by being placed near the glass, so as to receive the rays
as little broken and refracted as possible. Water should not be applied at
all, until vegetation has manifested itself, and afterwards, but
sparingly, whilst the plants are young, especially in prolonged periods of
dull sunless weather. Plants which are thus raised, should be planted out
as soon as possible, when their fibres are least numerous, as a means of
avoiding in part, the injuries to which they are exposed in
transplantation.

When the plan of depositing the seeds in the hillock of soil is adopted,
it is necessary to arrange the soil so that any subsequent additions made
to it, may not have the effect of covering too deeply the roots of the
plants, neither of burying the neck of the stem beneath the surface; it
should be arranged so that this latter may remain elevated above the
surrounding soil on the top of a slight mound, after the whole of the soil
is adjusted for the roots. I have already mentioned that the depth of soil
ought not to be at all considerable, but rather shallow than otherwise, so
as to expose the roots as far as possible to the influence of the sun.

It will have been seen that the plan of raising young plants from seeds,
has both its advantages and its disadvantages; and in order to avoid the
latter, and secure some of the former, the seeds should be sown early in
the autumn, whilst there is a sufficiency of heat and light, to mature the
growth they make previous to the dull cheerless days which mark the near
approach, and at length the arrival of winter. They will thus be endued
with the "stamina" necessary to sustain them, through that trying period,
and though not without difficulty, yet with comparative certainty, to
reward the well-directed zeal of the cultivator. It is impossible to give
any very minute directions as to the time of performing these operations
of propagation, for like all other gardening operations, it is not at all
requisite that they should be done on any particular day, nor ought they
to be done except when natural conditions are favourable to success: from
ten to twelve weeks generally elapse between the time of sowing the seeds
and the production of fruit, according as the season may be favourable or
otherwise.

The numerous hybrid varieties which are in cultivation, render it a matter
of some importance to make choice of those most suitable to the purpose;
these are however so continually changing, that it is useless to attempt a
record of them. The Sion house Cucumber is perhaps the best of all suited
for cultivation in the winter season. The principal features which are
required in Cucumbers for winter forcing, are, precocity; compactness of
growth, rather than luxuriance; prolificacy, rather than extreme length of
fruit; and hardiness of constitution: these, are to the gardener far more
important points, than those which entitle them to rank as "prize"
varieties.




CHAP. IV.

ON THE TREATMENT OF THE MATURE PLANTS.


From the time that the plants become established, which is the period of
their existence now about to be considered, they require to have the
elements of vegetable growth duly supplied to them, in order to secure
their successful developement. It is not enough to plant them in proper
soil, and duly to water them, unless attention is also paid to the
temperature, as well as the constituents of the atmosphere to which they
are submitted; neither will attention to these latter points be sufficient
to ensure success, if at the same time, the former are neglected. A _soil_
of suitable chemical, as well as mechanical composition, a pure and
wholesome _atmosphere_, _water_ promptly and properly applied, and _heat_
duly regulated, are conditions which equally require minute care and
attention in their adaptation; and these being applied upon the
comprehensive, and perfectly harmonious principles of nature, will leave
but little to be done in the shape of expedients, which are too frequently
resorted to, as the means of counterbalancing either defective or
unsuitable management. The application of these agents to the cultivation
of the plant under consideration, in the winter season, will form the
subjects of succeeding chapters. I will here briefly direct attention to
the importance of light in the growth of plants, and then devote some
space to the consideration of the subject of pruning and training.

Light is most essential to the perfect and healthy developement of
vegetable organization, the performance of the functions essential to the
health of plants being dependent on its agency. It cannot indeed be
assumed that plants will not continue to grow, unless they are supplied
with an intense degree of light; but it is certain that the successful
nature of their growth, their maturation, and their fructification, are
dependent in no ordinary degree upon the nature and force of its action;
for without it, the vital energies of animated beings are unable to
maintain and perform the processes of elaboration, and assimilation, upon
which their nutrition depends. The mere extension of vegetable tissue, may
indeed go on, though less satisfactorily, under the almost total privation
of light, but with the exception of cryptogamic vegetation, the organs of
fructification are not under those circumstances, produced at all: the
stem may be formed, but does not become solid: the leaves may expand, but
their condition is imperfect; and it is only by means of the full and
complete action of these organs in the nutrition of plants, that the
developement of the floral parts is brought about: the roots may take up
fluids, and these may be conveyed in the natural upward channels, and then
dispersed among the stems and the leaves; but it is the action of solar
light, aided indeed by the natural condition of the elements supplying
heat and moisture, which alone, by a process of elaboration, can convert
this fluid, once crude and undigested, into the compound organic
substances, such as lignin, gum, starch, gluten, &c. which in their turn,
are destined to minister to the support of the organs of reproduction.
Growth, that is mere extension, may go on in proportion as heat and
moisture are supplied to plants, but light is the agent to whose especial
influence we owe the production of their active properties and secretions,
and the perfection of their fruit.

If then light is so indispensable to the vegetable frame, how important it
is that the structures which we devote to the cultivation of such plants
as the Cucumber, which are naturally habituated to an eastern clime,
should be so designed, as to offer the least possible obstruction to its
entrance: how important, too, that the glass we employ, which in its
purest state, offers considerable obstruction, by refracting the rays of
light, should be as transparent and untarnished as possible, so as to
admit them as perfectly as can be practicable; instead of which, it is too
often disfigured by an accumulation and deposit of filth, which, to say
the least, must materially diminish their force: how important, moreover,
that whatever coverings it may be necessary to employ during the night to
prevent the outward radiation of heat, should be speedily removed in the
morning, and kept off as long as they safely may be, in order to permit
the inward radiation of light. When these matters are all duly attended
to, our climate, at least during the winter, still offers obstruction
enough to our success, in its mists, and fogs, its long dark nights, and
dismal cloudy days, and therefore wisdom would teach us, to avail
ourselves of all which we can grasp, by a course of untiring assiduity,
and attention to such apparently trifling matters as these.

The pruning and training of the plants, are operations, to which it will
be necessary to direct attention; and in the performance of which, the
circumstances which may have any influence upon them, as well as the
object in view, must be taken into consideration. The plants being
intended to occupy a surface of trellis-work in a line nearly parallel
with the glass, it will be requisite to train their primary shoots to a
sufficient length to reach from the soil to the trellis, before they are
what is technically called "stopped;" this operation, by removing the
central bud, or axis of developement, induces the buds which are latently
formed at the nodes of the branches, to push forth and become the axes of
further extension: two or three of the strongest of these lateral shoots
situated towards the top of the stem, should be retained, and trained on
the trellis in a direction towards the top of the house; these shoots
should be placed about 18 inches from each other, and when they have
reached about one-third of the length of the trellis, they also should be
stopped, and thus several more lateral shoots will be produced. The
uppermost strong shoot should in each case, be still trained in the same
upward direction, and the others must be disposed in the most convenient
form in the space between the main branches: these, that is the young
lateral shoots, if they do not shew a fruit blossom at the second joint or
leaf from the main branch, must be stopped, and the young shoot thus
induced to push forth, will in all probability have fruit at the first
leaf; if not, it must be stopped at _every leaf_ as it extends, until
fruit is observed. The upper portion of the branch after having extended
about one-third further up the roof, should be submitted to the same
process, and this must be again repeated until the whole of the trellis is
covered.

No reference has yet been made to the treatment of those lateral branches
where the young fruit are perceived: these should be permitted to grow
until the blossoms have expanded; and then, after this, they should be
stopped at the leaf next beyond the fruit blossoms. By permitting them to
grow until the flowers have expanded, the attraction of the growing branch
will continue to draw up a regular supply of nutriment, part of which will
be devoted in its course, to assist the developement of the blossoms; and
besides the advantage of the growing point acting thus as a sucker to draw
onwards the vital juices towards the young fruit, it will act also as an
outlet, to drain off what would otherwise be superabundant and dangerous
to these tender organs of reproduction. After the flowers have expanded,
this danger does not exist to so great an extent, the infant fruit have
new and important functions to perform, which are peculiarly their own;
and these call for a greater supply from the nutritive organs of the
plant: the stopping of the branch therefore, is the means of throwing in
this increased supply of food; but those who can most fully appreciate the
delicacy of the functions performed by the plant at this stage of its
developement, will most fully value the suggestion not to stop back the
growing branch _all at once_, but to do it by successional, though not
distant operations. The leaf which is directed to be left above, or beyond
each fruit, will serve, both as a reservoir, to receive all the
superabundant food, which may either be induced or impelled upwards; and
also, as a labaratory where this food will become purified and changed by
its exposure to atmospheric influence, amongst the lax tissue; and whence,
an appointed portion will be returned, and devoted by a process of
assimilation, to aid in the extension of the plants.

This system of pruning, with reference both to the barren and the fruitful
branches, must be continued, whilst these continue in a vigorous and
healthy condition; but when any symptoms of decay or of expended powers,
are perceived, they should be pruned quite away, and young ones encouraged
in their stead. All the pruning which has been spoken of, except the
occasional removal of a main shoot, should be done at a sufficiently early
period of growth, to admit of being effected by means of the thumb-nail;
for like all other plants, Cucumbers are much best treated, when whatever
pruning they may require, is done at that stage of growth, when the least
amount of trouble and labour is required to perform it. Pruning is not
under any circumstances a natural process, and when we have recourse to it
in artificial cultivation, it is only an expedient, which is rendered
necessary by the limited space, within which it becomes necessary to
confine the extension of the plants; and since this is the case, it is far
better to remove a portion of any plant, at an early period of its
growth, and thus to economize its vital energies, rather than to suffer
them to be expended, and the supply to become exhausted through a
superfluous developement, and then to deprive it of those very organs, by
the action of which, the expenditure would be again recompensed to the
vital energies.




CHAP. V.

ON THE NATURE, AND COMPOSITION OF THE SOIL.


Plants absorb fluids through the extremities or spongioles of the roots,
and it is thus that those portions of the substances which serve them as
their food, and are derived from the soil, are carried into their system,
in a state of solution: these spongioles are not strictly to be regarded
as analogous to the mouths of animals, for they are not provided with
openings, and cannot imbibe even the most impalpable powders; their action
seems to be more analogous to that of the lacteals in animals, for these,
as well as spongioles, serve to convey fluids only. These considerations
render it necessary, that in the composition of soil for the growth of
plants, the following important points should be held in
consideration;--it should contain a sufficient ratio of organizable
matter, that is of substances which can be rendered available as food to
the plants; it should readily absorb fluids, since it is only when in a
state of solution, that food can enter into the structure of the plants;
it should be sufficiently retentive to avoid the risk of injury by reason
of the evaporation, which takes place to a very great extent, when too
great an abundance of silica is present, or when more than a due degree of
porosity exists in its mechanical texture; and it should be sufficiently
permeable, to prevent any thing like excess of moisture, by stagnation.

Soils composed either principally, or almost entirely of heath soil, or of
vegetable mould, although very highly recommended for the growth of the
Cucumber in winter, are nevertheless objectionable when applied alone, as
will be evident if the foregoing principles are taken into view: it cannot
however be assumed that the plants will not grow in these soils, for they
grow vigorously for a period; neither can it be asserted that such soils
do not contain the qualities which are necessary to administer to the
nutrition of plants, for it is scarcely possible to conceive any
substances which are more nutritious, or whose application in this respect
is more effectual; but they are objectionable, in consequence of their
becoming soon expended, and failing to maintain for any length of time, an
equable degree of moisture. The cause which tends to produce this effect,
is the porosity, or the want of mechanical combination in the texture of
the soil; which being highly favourable to evaporation, is liable to
render it speedily, and very materially dry, when exposed to the influence
of powerful solar heat: the frequent application of water, does not
entirely obviate the objection, for even when so applied, it soon becomes
again evaporated, and thus tends to deteriorate the soil, and decrease its
fertility; this it does, by taking up much of the soluble matter contained
in it, and conveying it by evaporation into the atmosphere, instead of its
being taken up by the roots whilst in a fluid state, and applied to the
plant as a means of nutrition: when it is thus conveyed to the atmosphere,
the leaves though they are enabled to take up a portion of their food from
thence, are still incapacitated to do so fully, and hence, much of the
fertilizing properties of the soil, is carried off by the first current
of air which passes through the structure; and the plants decline by
reason of starvation, though they had been seated in the midst of plenty.

The soil which I should recommend for the growth of the Cucumber, would be
composed of ingredients, capable of supplying a sufficient portion of
vegetable food; of retaining a due portion of moisture, when placed under
powerful evaporation; and of securing the free passage of water through
its mass: the former of these conditions would be secured, by the use of
mould from the decaying leaves of trees, in the proportion of about
three-eighths; the latter would be ensured, by employing about one-fourth
part of turfy heath mould, and one-eighth part of clean coarse sand; and
the remaining quality, would result by combining these ingredients with
one-fourth part of good turfy loam. The preparation of this soil should
take place in the dry weather of the summer months, just previous to its
being used, so that it can be frequently turned and mixed, without
incurring the danger of reducing it to an adhesive consistency, which
would at once render it ungenial for the roots of plants: the turfy
portions both of the loam and heath soil should be piled up reversely,
until the herbage and roots of the grass, become partially decayed; when
required for use, it should be chopped into pieces of from two to four
inches square, by the spade, and then adding the other ingredients _in a
rough state_, the whole should be well mixed, without sifting, or any
other mechanical operation which would have the effect of destroying its
open texture. It should always be prevented from becoming saturated with
water; and moreover, should never be applied to the roots of plants which
are growing in a warm medium, without having been previously submitted to
a high temperature, for a sufficient length of time, to have absorbed at
least an equal degree of heat, with that in which the plants might be
already growing.

The admixture of charcoal with the soil, is said to be a means of adding
to its nutritive qualities. Charcoal, which is nearly pure carbon, may be
supposed continually to give off a portion of this gaseous substance
during its decomposition, and this uniting with a portion of the oxygen
contained in the air, would furnish a supply of carbonic acid gas, to the
atmosphere immediately about the plants. It should however be borne in
mind, that charcoal, is a substance whose decomposition except under the
influence of heat, proceeds very slowly indeed, and therefore its chemical
influence must not be overrated: doubtless however, the small portion
which does combine with the oxygen of the air, is directly beneficial to
the plants; for it is a function of the vegetable kingdom by the action of
their leaves, when under the influence of light, to decompose carbonic
acid, the oxygen of which is liberated, and the carbon fixed in the living
tissue. It is therefore probable that a supply of carbonic acid,
artificially maintained about the leaves and stems of plants, may be
beneficial to them, by furnishing them directly with a portion of carbon,
which they cannot absorb in a seperate state. When the charcoal is made
from twigs, and the small branches of trees, its decomposition is often
more rapid, than when it is obtained by the usual course of manufactering
it: if the latter kind of charcoal is employed, it should be broken into
pieces of a small size; and in ordinary cases, it should not be used in
larger proportion than with about twice its bulk of soil, with which it
should be intimately blended.

Besides its chemical action, which is probably beneficial, charcoal has a
decidedly advantageous mechanical action in the composition of soils, and
this is of a twofold nature:--first, in common with any similar
materials, it renders the soil "open," and thus effectually favours the
free passage of water through its mass: secondly, it serves as a perpetual
reservoir of moisture in the soil, for in consequence of its being
extremely porous, it imbibes a great quantity of water, by its force of
attraction, and this it parts with slowly to the soil; in this way, there
is no doubt that its action is most salutary. Probably a few pieces of
charcoal placed perpendicularly in the soil, and kept continually _wet_,
by the action of some little capillary contrivance, would serve as the
best possible means of conducting moisture, and distributing it to the
roots of plants.

It will be observed that the application of dung, in any way whatever, has
not been recommended; neither do I consider it to be at all requisite, or
desirable, in the culture of winter Cucumbers: luxuriance is not a
consummation which it is at all desirable to attain to, a moderate, well
matured growth, being far preferable; and as some care is supposed to be
used to provide suitable soil, it should be of such a nature as to possess
the properties, which are requisite to effect the desired end. Dung
containing as it does fertilizing properties, may do well to renew the
fertility of exhausted soils, which may have been under a long course of
cultivation; but it is questionable, whether it ought to be admissable to
any extent in pot culture, or in the growth of forced plants, in
preference to a supply of wholesome unexhausted natural soil.

A very great objection to the use of dung when applied in a solid state in
the composition of soils, consists, in its being presented to the roots of
plants, not only in the advanced periods of their existence, but equally
so, during the early stages of their growth; here must be an error, for
infants, whether they belong to the animal or vegetable kingdom, are
certainly not capacitated to appropriate the same kind of food, in the
same proportion, as adults. If only a small portion of soil is at first
employed, and portions more and more enriched, are from time to time
added, as the roots may extend, we are still liable to stumble on an
objection, almost as important, though of a somewhat different nature; for
we can in that case scarcely fail to injure the spongioles of the roots in
a greater or less degree, and the injury thus sustained, will consequently
act as a check in the progress of their developement. These considerations
seem at once to mark the propriety of applying liquid manures in highly
artificial cultivation; they can be supplied in this state, when the
plants are in such a mature and advanced state of growth, as from time to
time to require their aid; and their fertilizing properties being held in
solution by the fluid medium in which they are conveyed, they are just in
the condition to be taken up at once by the rootlets. It must still
however be recollected, that whilst even impalpable powders cannot as such
be made to minister to the nutrition of plants, so neither can gross
liquids effect this purpose: it is clear limpid fluids, only, which can be
received by the delicate spongioles, and therefore the so-called manure
water, when applied of the consistency of mud, is not only in an unfit
state to effect its purpose, except by the addition of a more bountiful
supply of pure liquid, but it is also liable to act injuriously by reason
of the concentration of the strength or powerful qualities of the manure,
and by counteracting the open texture of the soil. Manure water,
therefore, from whatever source it may be derived, though not necessarily
a colourless, should without question, be a limpid fluid; if otherwise
applied, it will at once destroy one of the best qualities a soil can
possess, viz. porosity.




CHAP. VI.

ON THE APPLICATION OF MOISTURE.


From what has been stated in the preceeding chapter, it will be
sufficiently evident, that a supply of water is required as a component of
the soil, in which all plants are grown, in order to enable them to draw
from it, other components, which form their food; and that, as it is
necessary for them continually to take up a portion of this food, so is it
necessary, that moisture should be continually present, in order to render
it available by them.

Among other conditions to which the operation of applying water to the
soil should be subjected, there are some which are specially important: it
should never be either applied in _excess_, or unduly withheld; nor should
it ever be applied when of a temperature below that of the atmosphere in
which the plants to whose roots it is applied, are growing at the time of
its application.

There is a liability of applying water in excess, when the particular
stage of growth, the peculiar state of the weather, or the season of the
year, are not duly regarded: thus, an adult plant will consume more water
than an infant plant; and any plant, will decompose a larger quantity of
water, in sunny weather, when evaporation is going on briskly, than in
cloudy weather, when it is scarcely perceptible; again, in the summer
season, a much larger quantity will be appropriated, than in the winter.
Water has been applied in excess, whenever the soil becomes soddened or
saturated therewith; but great as this evil is, it is equalled in its
injurious effects, by falling into the opposite extreme, and withholding a
quantity sufficient to render the constituents of the soil, available as
food to the roots of plants placed in it.

The necessity of applying water, of a temperature equal to that of the
soil, is rendered evident by a reference to the natural conditions by
which the soil is watered. In a small and nearly globular form, the water
gathered up by the action of the sun, and forming the clouds above us, is
precipitated through the atmosphere, and there its temperature becomes
equalized or assimilated with that of the medium through which it has been
passing; and although in our own latitude, we perhaps fail to discover any
material degree of warmth in the drops of rain as they fall, yet in
eastern climes, we cannot but imagine, that after having been submitted in
the thin strata of the clouds to the action of the sun, they must
previously to entering the soil, have imbibed some portion of heat.
Moreover, the importance of maintaining a gentle bottom heat, at the roots
of forced plants, renders it necessary to avoid any application, which may
tend to lesson its effect, and submit the roots to any chilling influence.
The temperature of the soil is naturally above that of the atmosphere, and
as the application of moisture by exciting evaporation, has an abstract
tendency to lower the temperature, it should therefore, when applied, be
in a slight degree warmed, so as thus to increase rather than diminish the
heat contained in the soil.

As some moisture in the soil is necessary to render the food contained
therein, soluble, and available to the spongioles of the roots, so
moisture in the atmosphere is essentially necessary to assist in applying
the gaseous elements of that elastic compound fluid, to the nutrition of
plants by the action of the leaves: without moisture in the atmosphere,
the leaves and outer covering of plants would become dessicated, and the
stomatas shrivelled up and closed, so that neither the exhaling nor the
imbibing functions of the plants could then be carried on.

The moisture of the atmosphere, then must not be neglected; not only
because the healthy action of the vital organs of the plants depends on a
proper hygrometrical state of the atmosphere, but, inasmuch as it is the
readiest means both of avoiding, and when unhappily, they are present, of
destroying, many of the most destructive and troublesome insect enemies,
to whose depredations, plants are subject.

When a moist atmosphere is duly and regularly maintained, there is but
little fear need be entertained of the establishment of a colony of
insects--such as the thrip, and the red spider, which are perhaps the
greatest pests which have to be overcome in the forcing house; nor is
there a more effectual method of destroying them, than by applying a high
temperature in conjunction with an intense degree of moisture. To the want
of a balance of moisture in the composition of the atmosphere, and in the
soil, too, rather than as is commonly supposed, to an excess of it in the
former, is the appearance called mildew to be attributed; this it
occasions by checking the regular action of the perspiratory organs, and
thereby inducing an eruption of the cells of the tissue: the extravasated
sap lodging on the cuticle, affords a nidus for the germination of the
sporules of that particular fungus, which when grown, is the mildew: the
remedy consists in avoiding an irregular composition of the atmosphere, as
regards heat and moisture; and also an excess or deficiency of moisture in
the soil, so that each may be in a condition to exert its proper influence
on the constitution and developement of the plants. Canker, another
disease, to which Cucumbers are sometimes subject, appears to be produced
by too low a degree of temperature, accompanied by an excess of moisture,
both in the soil and the atmosphere, and it generally attacks those
particular parts, where any check or obstruction is offered to the flow of
the sap, such as that occasioned by a wound, or even the ramifications of
the stem: this suggests that its remedy, would consist in a due regulation
and balance of the constituents of the atmosphere, and the soil.

Moisture is generally applied to the soil by being poured directly on it,
and to the atmosphere, by means of the syringe, and the use of evaporation
troughs. When applied to the soil only from the upper surface, there is a
liability of its failing thoroughly to moisten it, and by reason of this,
together with the constant action of the heat from below, by whatever
means heat may be applied, the soil is frequently found to be dry beneath,
when the appearance of the surface might lead to the supposition that it
was sufficiently moistened.

By a reference to the sketch and description already given, it will be
seen, that a provision is there made, whereby water can be poured in
quantity _beneath the soil_, immediately on the top of the tank, whence in
the form of vapour it will rise among the soil, and thus render it
thoroughly moist; at the same time, it can be applied to the surface,
whenever it may become necessary to do so. The moistening of the
atmosphere will also be fully secured by the mode of ventilation which is
there proposed, for the air, at the same time that it is warmed, will
become charged with moisture in a ratio equal to its temperature, before
it enters the house. If it becomes requisite to admit moisture without
changing the volume of air, it can readily be effected by opening the
tubes or shafts inside the house, without opening the exterior
ventilators; and when dry heat may be required, it can be secured by
closing entirely the communication with this reservoir of moisture, and
the hot-water pipes will then radiate any quantity of dry heat that may be
required.

By means of a due application of these provisions, an equable degree of
moisture beneath and among the soil, as well as in the composition of the
atmosphere, can be secured with perfect ease, and a trifling amount of
labour.




CHAP. VII.

ON THE REGULATION OF THE TEMPERATURE.


If we figure to our minds, a plant which in its native habitat enjoys a
climate far more genial, and a temperature far more elevated, than our own
country affords, it must be obvious that some regulation, and increase of
temperature, either positively, by the artificial application of heat, or
negatively, by affording shelter and protection, will be required in order
to ensure any degree of success in its cultivation. The Cucumber is a
reputed native of the East, and we have therefore in this supposed fact,
an indication of the nature of the climate, which it should be our object
to provide for it; but still it must be borne in mind, that in conducting
any system of artificial cultivation, it is not at all times desirable, or
even safe, to supply a resemblance to any part of the natural
circumstances affecting the growth of a particular plant, unless we have
the means of supplying the _greater part_, or _all_ the conditions which
exist in a state of nature: this I shall again have occasion to refer to.

By another step we arrive at the conclusion that the standard of
temperature, to which the Cucumber is submitted in its cultivation in this
country, is a point, varying with the individual opinion of cultivators;
as some may take a part of the natural conditions of growth as their rule;
others, all these circumstances; and others, again, various combinations
of them.

Referring back again to the provisions of nature, we can scarcely hesitate
to conclude, that in clear sunny weather, the temperature to which the
Cucumber is submitted, _cannot within reasonable limits_, be permitted to
rise too high; whilst at other times, when the weather is dull, or cloudy,
and always at night, a much lower degree of heat ought to be applied. In
sunny weather, the natural agents which cause excitement and activity of
the vital functions, are in full action; and consequently at such periods
we may rationally indulge in the application of those exciting agents
which are under our controul--always however bearing in mind, that we must
not unduly apply one agent, when we either cannot, or neglect to apply the
others also. On the other hand, in dull weather, and at night, the source
of light being in the one case absent, in the other obscured, a
comparative state of lethargy or repose is prevalent, and the natural
functions of vitality are but feeble in their action, if not in some
cases, absolutely in a quiescent state; with such a state of things
existing, it is barely rational to apply stimulants, and to induce
unnatural excitement. The application of exciting and stimulating agents
at such periods, may be compared in its effects to the excitement of a
frightful dream acting on the human frame; the vital functions--not the
vitality itself--cease during sleep, and both the animal and the vegetable
should be at rest; excitement acts on both by deranging the system, at
least for a time, and since a succession of these derangements are known
to produce injurious results, we may be certain, that each seperate
instance must have an evil tendency.

In applying this practically, to the case before us, it may be
recommended, that the temperature in which Cucumbers are grown during
winter, should not fall much below 60° Fahrenheit, at night; and in the
day time it should not rise above 70° in dull weather, by the aid of heat
artificially applied; in clear weather, by the influence of that glorious
source of light and heat, the sun, it may be safely allowed to rise to
80°, or a little higher, before air is admitted. A somewhat higher range
may be permitted, as the days lengthen, and the influence of the sun
becomes more powerful; thus at night, it should not rise over 65°, by day
75° to 80°, and by sun heat to 90°. Thus it will be seen, that I have
recommended the regulation of the temperature of the internal atmosphere,
by that which is external; and it is my firm conviction that inattention
to this simple rule, is the source of much of the failure, which is
experienced by some of those who attempt the growth of plants, at any
other than that, which may be regarded as their natural season of growth.
It appears to me, most unreasonable, to aim at attaining any particular
point of the thermometer, merely because any particular season of the year
may be present, or any particular stage of growth attained. Even if in the
sunny climes, from whence the Cucumber has been transmitted to us, there
exists such an equality of temperature and atmospheric serenity, as some
cultivators attempt in the growth of these plants; it surely cannot be
consistent in us to equalize and elevate the temperature of our artificial
atmospheres, when we cannot supply them at the same time with the same
intensity of light, or provide for them the same serene and unclouded sky.
It should rather be our object to adapt the plant to the climate of our
country, since we cannot change the climate to supply the natural
circumstances, with which the plant is favoured; and acting on this
principle, we should never aim at supplying the agents which would induce
a premature and therefore debilitated developement, when the whistling
wind, and the drifting snow, tell us that Nature, would have, at least the
members of her vegetable kingdom, be at rest.

Since however, it is apparent that during the depth of the winter season,
at least when wintry weather is present, the progress of plants in an
artificially heated atmosphere, ought not to be rapid, or unduly forced;
it by no means follows that no progression at all should be made: the
elements of growth maybe supplied; but the application of them should be
guided by moderation, being lessened at those particular periods when the
weather is least propitious, and increased during those periods when it is
most favourable. In the works of Nature we may ever learn a lesson of
consistency, for they are perfect: they teach us that food is requisite to
maintain the life of all those objects which are endowed with it; that
that food must undergo a process both of digestion and assimilation, ere
its purpose is fulfilled; and that each of these processes depend on the
action of natural agents. In the vegetable kingdom, heat and fight as
derived from a united source, are the agents appointed to bring about
these results, and in order to ensure their proper action, they must both
be present in a powerful degree: in artificial schemes of culture, we can
command a supply of the one, but the other is not within our power; our
consistency therefore depends on our applying so much of the one under our
controul, as will secure the united action of it, with the existing degree
of the other--consequently, _when light is absent, or deficient, heat
should also be diminished; and when light is present and abundant, heat
may safely be increased_.




CHAP. VIII.

ON THE ADMISSION OF AIR.


The question of the admission of air, is one of some importance. It is an
opinion, which was I believe first publicly brought forward by the late
Mr. Knight, that an influx of a large volume of the external atmosphere,
to the interior of forcing houses, is by no means requisite, and is often
the source of very serious evils. Were it for no other reason, than that
of avoiding the chilling influence of cold air on the tender tissue of
plants growing in a high temperature, I should feel inclined to support
such a view; but when there are facts sufficiently abundant, to prove,
that plants do not themselves vitiate the air of such structures to an
extent sufficient to render it unfit for their continued growth, or at
least, that a sufficient interchange is constantly going on, without
opening the sashes of a forcing house, the evidence appears to be
overwhelming; and the necessity of continuing a practice so fraught with
danger, and so frequently attended with disappointment, appears to be done
away.

The injury done to the tender foliage of plants in forcing houses, by
contact with cold air, results from the increased capacity of air for
moisture, as it become heated. When cold air is admitted to these
structures, it cannot contain so great a quantity of aqueous matter, as it
is capable of taking up when it becomes warmed: this increase of
temperature, is soon in great measure, supplied to it, but rarely is a
sufficient quantity of moisture, at the same time within its reach, to
enable it to supply its increased capacity for aqueous matter: the
consequence is, that on coming in contact with the foilage of the plants,
which is of a succulent nature, and contains a great proportion of water,
the warmed air continues to abstract a portion of moisture from the
plants, until its capacity is satisfied; and hence the plants are robbed
of their "life's blood." Besides this action, which is the cause of
serious evil, the tissue itself is contracted and thereby injured, by
reason of the degree of cold, which is at the first gush, liable to come
in contact with the warm foliage. These remarks apply to cold air, when
admitted in a large bulk, by opening the sashes; and when a draught is
produced, by opening them, both at the back and front, and the top and
bottom of the house.

Deterioration of the air, by the action of the functions of the plants,
could not take place, except in hermetically sealed structures: for by
reason of the expansibility and elasticity of air, when it becomes at all
heated, it not only gains egress, but also admission through the most
minute crevices: that this interchange is sufficient to counteract any
deteriorating influence which the plants might have on the internal air,
with respect to their continued existence in it, is abundantly proved by
the growth of plants in Ward's cases, from the interior of which the
external air is excluded as fully as it possibly can be, without their
being actually sealed: if therefore, any injurious effects result to
plants, from their being cultivated in a close atmosphere, we must seek
for the cause, in some other source, than the plants themselves. If any
noxious qualities exist in the atmosphere of structures, to which the
external air has not free ingress, they must result from some neglect or
ignorance on our part, in suffering extraneous and unwholesome matters to
accumulate in such situations, and there to decompose, and enter into
combination with those gaseous bodies, which form the volume of the
internal atmosphere of our plant structures. The existence of such
extraneous matters, may indeed be traced to various sources; and they may
be present, even when much vigilance is employed to prevent their
accumulation; and therefore, as an inconceivably minute quantity,
inappreciable to the senses, would frequently be sufficient to effect
deterioration, it is possible that these impurities may often originate in
sources which are least of all suspected. The decomposition of organic
matter, whether animal or vegetable, may frequently be the source of
injurious results in this respect; for although this is principally
resolved into those elementary gases, which appear to form the basis of
all created objects, yet there are other matters liberated, which may then
enter into fresh combinations; and either this, or a disproportionate
accumulation, even of these elementary bodies, may reasonably give rise to
serious apprehension, and demand the exercise of discretion, in order to
prevent them from becoming injurious. Besides this, these decomposing
bodies, afford just the very state of things, which appears to be
requisite to call into existence, and developement, a numerous phalanx of
cryptogamic vegetables: not that such matters, can for a moment be
rationally considered to generate, these _cellulares_; but that they
afford a suitable pabulum, and medium of developement for those millions
upon millions of sporules, which we may readily conceive to be dispersed
in the atmosphere; and with which it may be teeming, though from their
buoyancy and minuteness, they may float to us invisibly therein.

The admission of the external air, by the ordinary process of opening the
sashes of forcing houses, has been said to be unnecessary, or at least by
no means important, in so far as the function of vegetable respiration is
concerned, because the buoyancy of the air within all such structures,
would enable it to escape in sufficient quantity through their openings
and crevices, to counterbalance any thing like deterioration, which might
by any means result from the vital action of the plant. The admission of
external air, is also directly injurious to forced plants, during the
winter and spring months, when a very material difference of temperature
exists between it, and the internal volume, by contracting the vessels,
impeding the circulation of the juices, and thereby checking the regular
course of the growth of the plant. If these reasons fail to stamp it as a
practice which ought not largely to be indulged in, it is further
objectionable, as being productive of a prodigal expenditure of fuel:
there can be little doubt but that generally speaking, a far greater
quantity of fuel than is requisite, is expended in maintaining the
temperature of forcing houses, solely from this cause; for the cold air
when admitted, continues to abstract a portion of heat from the warmed
air, until the temperature of both becomes equal, and consequently an
increased application of fuel is requisite, in order to raise the newly
admitted air to the same temperature as that which has been suffered to
escape; and as the buoyancy of heated air is so great, an immense volume
must necessarily rush out through a very small aperture, and thus there
must also of necessity be an immense waste both of heat, and of fuel. A
given portion of fuel, in its combustion, can give off but a certain
proportionate ratio of heat, and if this is allowed unnecessarily to
escape, the prodigality is self-evident. It is but a weak argument, which
would seek to give to the admission of cold air, the office of regulating
the temperature of plant houses; this ought to be effected by limiting the
degree of heat _applied_, and not by attending to the _abstraction_ of
that which had been previously administered with two lavish an hand.
Besides the extravagance of such a course, the constitutional vigour and
energy of the plants is at the same time sacrificed by undue excitement.
The admission of cold air in large quantities, therefore, brings
condemnation in its train, since it is unnecessary, and extravagant, as
well as directly injurious.

There are nevertheless some considerations which render the admission of
air, when regulated and applied with discretion, an operation of
importance to the health of plants: it is productive of beneficial
effects in carrying off the noxious vapours, which may although unseen,
and guarded against, still float in the atmosphere; and there can be
little doubt that another beneficial influence which it exercises, results
from the motion which is produced by a body of air changing its position,
which probably promotes circulation, and increases the excitability of the
plants.

Since therefore a change of the volume of the atmosphere in plant houses,
is productive of benefit, and the admission of a large body of cold air,
is at the same time so decidedly objectionable, it is important, that in
endeavouring to secure the benefits of the practice, the injuries which
are liable to result, should if possible be avoided. The regulation for
the admistion of air, which is described in the second chapter of this
treatise, may be regarded as being of some importance in this respect, as
well as in the provision which it includes, of supplying the heated air,
with a due proportion of moisture.

Physiologists tell us, that plants derive a considerable proportion of
their food, directly from the atmosphere, by a process similar to the
inhaling of animals; and that the substances thus derived, are carbonic
acid, ammonia, and water, which contain the elements of organic matter in
considerable proportions. The influence of the atmosphere is exerted
beneficially, by its constituents entering into combinations with other
matters, which are taken into the system by the roots, and spread out and
exposed in the leaves: this exposure has so far the effect of altering the
character of the substance carried up from the roots, that it is no longer
a body of crude juice, but is undergoing a process of elaboration, and is
being assimilated with the superincumbent tissue of the plant. There seems
to be no reason why those particular gaseous bodies which plants
appropriate to themselves from the atmosphere, should not to a great
extent be supplied to them artificially, at such periods as it may be
necessary, or desirable, to accelerate their growth, and induce a more
perfect and mature developement. It has been already stated, that the most
important of these aeriform bodies, are nitrogen, which plants derive from
ammonia; and carbon, which they derive from carbonic acid gas, on the
liberation of the oxygen, which is one of its constituents; neither of
these, can however be appropriated, when in a free state, but only when in
a state of combination, and forming either a gaseous or a fluid body. It
is probable that nitrogen might be supplied to plants, through the medium
of the atmosphere in an artificial manner, by placing within any
structure, a portion of some of the volatile salts of ammonia, which
latter being given off, would at once supply the demands of vegetation.
Carbon might be applied, by the use of charcoal; and it is worthy of
experiment how far the _combustion of charcoal_, in plant structures, by
accelerating the formation of carbonic acid gas, may have a beneficial
influence on vegetation. The use of charcoal as an ingredient in the soil,
though doubtless partly, and perhaps principally mechanical, is
nevertheless in all probability rendered advantageous in this very way;
the slowness of its decomposition must however render the quantity
applied, very homoeopathic in its nature.

A series of experiments with the view of ascertaining the practicability
of continually supplying to the atmosphere, those qualities which plants
abstract from it, and of determining the manner, and the degree in which
they should be applied, would be one of the most interesting and important
matters, to which the minds of Horticultural reformers could possibly be
directed; but it is most essential, to remember, at the same time, "that
these are powerful agents, requiring much skill in their adaptation," and
capable of effecting serious injury and disappointment, if
indiscriminately applied.




CHAP. IX.

ON THE GROWTH OF MELONS.


It is barely possible to suppose any use to which a structure which during
the winter season had been devoted to the growth of Cucumbers, could be so
legitimately appropriated in the summer, as that of the growth of the
finer Melons of Persia, Cashmere, and the East. The superiority of such as
these, in every point of view, over those kinds, which have been long in
cultivation, would be an ample recompense for the appropriation of such
valuable space to their use; whilst in no other structure could the
peculiarities of the treatment they require, be so fully complied with,
and be rendered so completely under control, as in that under
consideration.

There are some peculiarities in the treatment of these Melons, to the
consideration of which, it may be desirable to devote a brief space; the
most important of these, are the composition of the soil, the application
of moisture at the root, the regulation of atmospheric warmth, and also,
of atmospheric moisture; in these particulars, they offer some differences
to what has been previously stated, with reference to the Cucumber.

The soil in which the Melon delights to grow, is one of a more compact
texture than is usually regarded as applicable for the Cucumber: a
suitable compost consists of the "top spit" from a loamy pasture, of a
texture _rather adhesive_, and retaining the herbage and roots of the
grass; this should be collected a few months before it is used, so that
these vegetable substances may be in a _decaying_ state, and it should be
broken roughly to pieces, but by no means sifted; to it, should be added,
about one-fourth part of vegetable mould: the whole should be well
incorporated, and, before using, should be placed in a situation where it
may not be liable to become saturated by heavy rain; which would serve to
destroy the free and open texture, which it is so desirable to retain.

In the application of moisture to the soil, the structure which is
described in a previous chapter, will be found to present facilities,
which peculiarly adapt it for the growth of these plants. In Persia, and
the neighbouring countries, where the Melon is so successfully grown, the
ground is irrigated by means of numerous channels, which, from the
limitation of their exposed surface, are not peculiarly adapted to supply
atmospheric moisture; but are yet sufficiently numerous to secure the
perfect irrigation of the soil, within the reach of the roots. The tubes
or shafts, represented at (_n_) in the sketch referred to above, are
intended to communicate directly with a layer of coarse open material,
extending entirely over the top of the tank, and beneath the soil; by
means of these a supply of water should be poured beneath the soil, which
will thus keep that portion immediately about the young roots, in a
constant and complete state of saturation, by means of the steam which
will arise, in consequence of the heat from the tank. A uniformly warm,
and a thoroughly moist soil, will be thus easily secured, which are two
important points in the growth of Persian Melons. It must be recollected
that these conditions for supplying moisture, are recommended only during
the time of growing the plants, and swelling the fruit; but as these
latter approach their maturity, the degree of moisture must of course be
gradually diminished.

In connection with this moistened and genial soil, the Melon has
naturally the advantage also, of powerful sun heat, and intense light; and
these are two conditions which it is indispensable should be supplied in
artificial cultivation, as fully as they can possibly be obtained. It is
by means of the moisture of the soil, that the plants are enabled to grow
on rapidly and vigorously, because that moisture renders the food
contained in the soil, soluble, and therefore available to the roots; but
the elaboration and assimilation of this food depends on the degree of
_light_ and _heat_ with which they are supplied: without these conditions,
to convert the crude sap, by their united agency, into organic compounds,
such as lignin, gum, starch, and sugar, and to induce their deposition,
the fruit will indeed be formed--it will grow, and perhaps may even tempt
the eye; but unless these chemical and vital changes have taken place in
its constituent parts, the eye, as it frequently happens, will have been
deceived; and instead of the palate being gratified by a mature and
luscious fruit, it will find nothing but a tasteless mass of pulp. The
plants, therefore, cannot, in our latitude, receive too intense a degree
of solar heat, or of light.

The same cause which renders the natural atmosphere of the Melon countries
elevated in temperature, renders it also comparatively dry; the sun drinks
up the moisture which is deposited near the surface, or which may rise to
that position; and by an exceedingly powerful influence effectually
prevents the accumulation of moisture about the exposed parts of the
plants. The atmosphere is nevertheless not in an arid state; the
evaporation from a well-moistened soil effectually prevents this from
being the case, but the excessive heat also as effectually and continually
prevents an undue accumulation of moisture in the atmosphere. The
application of this fact, to artificial practice, is plain; a less amount
of moisture artificially applied, in comparison with the temperature, must
be permitted, than when the cultivation of those plants is attempted whose
natural habitats are less strongly featured in this respect.

Such considerations as these naturally force on us the conclusion, that it
is vain to attempt the cultivation of this noble fruit, except during that
portion of the year when the sun exerts his greatest power in our
latitude. It is not because they cannot be induced to grow at any other
period of the year, for the mere extension of vegetable tissue will go on,
though the influence of the natural agents is but limited and feeble; but
it is because maturity, perfect development, and, above all, the full
assimilation of the sap, cannot take place sufficiently to ensure a good
flavour in the fruit, except light and heat are not only unimpeded and
constant, but powerful and united in their action.




CHAP. X.

CONCLUDING REMARKS.


I will here briefly recall attention to a most important point which the
cultivator should continually keep in view: it is most important that he
should _study Nature_; for if we may believe our senses, or place any
confidence in overwhelming evidence, we may be certain that all the
conditions we observe in a natural state of things, have been planned by
an All-wise hand; and further, that a finite mind can never attempt with
success, either to surpass or to dispense with any portion of that which
an infinite being has ordained. "Order is Heaven's first law," and in
whatever we may attempt to do, we shall not be wise, if we endeavour to
effect our purpose by any means which may distort the fair proportions
which unaided nature presents to our view. In cultivating plants,
therefore, we should administer the conditions which are favourable to
their growth and development, in somewhat the same proportions each to the
other, in which they are naturally blended--not supplying one essential,
in an undue manner, and, at the same time, neglecting others; for
successful cultivation must ever depend upon the connection and influence
of numerous circumstances upon each other, and can never be attained,
unless these conditions are complied with, either designedly, or, as it
often happens, by mere accident.

Another point which it is important to keep in view, is that instructions
should be studied, rather than copied, in their application to practice.
No instructions can be given that should be blindly and implicitly
followed. The circumstances under which plants are placed are varying
every day, and even every hour, and, to be successful, horticultural
practice must be varied also. It must, however, be varied according to
principle. But even what are regarded as established laws and principles
should not be heedlessly followed; to be truly successful, a man must not
only be a practical enthusiast and a keen theorist; he must also be a
skilful experimentalist: his experiments and their results, if carefully
watched, deduced, recorded, and studied, will serve to guide him for the
future.




APPENDIX.


_On Heating, Ventilating or Aerating, and Covering._

Since the publication of the first edition of this work in 1844, the views
expressed in the second chapter, with reference to structures best adapted
for Cucumber culture in the winter season, have met with much
corroborative support. Respecting the questions of heating, ventilation,
and covering, a few more words may be added.

I have before recommended hot water tanks for supplying bottom heat, with
attached pipes for the circulation of hot water to warm the atmosphere. I
can see no reason for recommending any other arrangement now; for the
experience of successive years goes to show that hot water, applied on
sound principles, is, above all other means of heating, effective in its
operation; and as to the question of expense, raised as an objection to it
by some, it is sufficient to say, that, although one hot water apparatus
may be fitted up in an expensive manner, another may be rendered perfectly
successful in its operation, at the same time that it is extremely simple
in its arrangements, and correspondingly inexpensive in its cost.

A seeming error in the engraving, at p. 18, has been pointed out to me. In
the description of the sketch it is stated that, "a series of pipes
attached to the same boiler [which heats the tank] would supply the
requisite heat to the atmosphere." The sketch itself shows these pipes to
be considerably above the level of the water in the tank, and where they
could not, consistently with the other arrangements, be thus employed.
This may be explained thus:--the sketch was introduced rather for the
purpose of illustrating certain proposed arrangements, as regards bottom
heat and ventilation, than as furnishing an exact and detailed design for
a model structure; and thus it happened that the pipes were merely shown
to be placed at the front part of the house, to indicate that this was
their proper relative position. There would be no practical difficulty in
placing the pipes lower down, and nearly close to the front wall, so as to
admit of the proposed connection; all that would be required to effect
this, being to fix the slab, on which they rest--and which prevents the
air from rushing upwards into the atmosphere of the house at this
point--in a sloping position, instead of a horizontal one.

The principle involved in the plan proposed for aëration or ventilation,
is no doubt a sound one; and though the plan which is more particularly
described may be modified and varied, yet it is believed to be efficient
for its intended purpose.

There can be no doubt that the admission of cold air to a structure in
which tender plants are being forced, either during winter or early
spring, is materially hurtful to the plants, in proportion to the
tenderness of their constitution; and the Cucumber being, under those
circumstances, a plant of a very tender and delicate nature, is especially
susceptible of harm from this source. As a consequence resulting from this
fact, there can be little hesitation in affirming that whatever fresh or
external air it may be necessary to admit, during the period referred to,
should be warmed before it reaches the plants, and in being warmed not
burned, but supplied with the additional moisture its increased heat
capacitates it to take up, and which, to be congenial to vegetation, it
requires. This is provided for by the plan already recommended, where the
cold air is made to pass through the tank containing the heated water
which warms the soil. By a perfectly practicable modification of this
arrangement, not only may this result be secured, but also the continual
circulation of the internal atmosphere may at pleasure be assisted and
accelerated, during the time when it might not be necessary to admit fresh
air. This would be an additional advantage. The arrangement proposed to
effect this, is to conduct the cold external air through a heated chamber
containing the tanks--these latter being covered, but also admitting of
being opened to any extent to supply moisture or steam in the proportion
required. The cold air, after passing upwards through the chamber, escapes
at the front of the house, and ascends to the upper part of the house,
from whence it finds its way downwards near the back wall, and there again
enters the chamber, through openings provided for the purpose. The
circulation of the internal atmosphere would be thus facilitated and
accelerated, even without the admission of any current of external air,
for, of course, there is more or less of this kind of movement going on in
the atmosphere, wherever and in whatever form a source of artificial heat
is present. Another mode of combining internal atmospheric motion, with
ventilation, and by which the cold air is warmed before it reaches the
plants, has been practised with very marked success, in a vinery at
Park-hill, Streatham, Surrey; and I have described it in the _Journal of
the Horticultural Society_[1] as follows:--"This plan consists in passing
a zinc pipe, thickly perforated with small holes, from end to end of the
vinery, and exactly beneath the range of hot water pipes, which heat the
structure. In the outer [end] wall, communicating with this perforated
pipe by means of a kind of broad funnel, a register valve is fixed, by
which the admission of air can be regulated with the utmost nicety, or the
supply be shut off altogether: this valve is fixed a little below the
level of the perforated pipe. The action of this contrivance was evident
enough from the motion communicated to the foliage of the vines; and its
effects were apparent in the unusually healthy and vigorous appearance
they bore, until their period of ripening. In this case, sufficient
moisture was kept up by syringing the walls and pipes, wetting the
pathway, and by the use of evaporating troughs, placed on the metal pipes,
and kept constantly filled with water."

In another communication published in the work already quoted,[2] after
alluding to the now well-known garden truism, that a comparatively low
night temperature is indispensable to the maintenance of vigorous growth
in plants of all kinds, I have advocated a more extended adoption of the
practice of night covering hot houses, as a means of permitting the low
night temperature required, and at the same time securing the plants
against the extreme cold to which they would thus be sometimes liable.
From the changeable nature of our climate, there is some difficulty in
apportioning the degree of applied heat, so as to suit exactly the
requirements of the plants in these respects; and it is especially
difficult to maintain with certainty the low degree of night temperature
which would be desirable, and at the same time avoid risking the safety of
the plants, through a sudden declension of the temperature of the exterior
air. At present this difficulty has to be met by extraordinary care on the
part of the gardener, and often by serious encroachments on his proper
time for study and for rest: even then sometimes without success. This end
would be much more effectually and certainly secured by a _complete
system_ of covering hot-houses and forcing-houses; and this plan would
secure the further advantage of avoiding the undue stimulation of the
plants by a then unnecessary amount of heat, applied solely to prevent the
very evil which covering also prevents, namely, the risk of excessive cold
during the night.

The principle upon which a covering acts most efficiently, is that of
enclosing a complete body or stratum of air exterior to the glass, this
body of air being entirely shut away from the surrounding outer
atmosphere. Air being a bad conductor of heat, the warmth of the interior
is by this means prevented from passing to the exterior atmosphere; or, in
other words, the exterior atmosphere, being prevented from coming in
contact with the glass, cannot absorb from the interior any material
proportion of its heat. To secure this advantage, however, the coverings
_must_ be kept from contact with the glass, and they should extend on
every side where the structure is formed of materials which readily
conduct heat--such as glass or iron. The coverings should in fact form
neither more nor less than _a close outer case_.

One point connected with the application of these coverings, which I
consider would constitute an improvement, and which, as far as I am aware,
has never been acted on, is that of having them to fit so accurately as to
exclude the external air (a matter of no difficulty in the degree
required), and then to have a series of ventilators provided, to stand
open during the night, whereby an interchange of the atmospheric volume
would take place throughout the night, without exposing the plants to
contact with cold air. The stagnation of the internal atmosphere would
thus be prevented, in consequence of the interior air and the air between
the glass and the covering being of different degrees of density, owing to
their being differently charged with heat. By this plan, therefore, I
conceive that direct benefit would accrue to the plants; and it would also
materially assist in preserving that cooler--but not cold--night
temperature, which the fear of injury from frost prevents from being more
fully realised in ordinary cases.


[Illustration]


The annexed diagram represents one of the many ways in which this idea
might be carried into practice. It will be understood that, as here shown,
the side shutters and end shutters (the latter not indicated), fit into
grooves, the upper groove being attached to iron pins, and thus fixed at a
proper distance from the building, without obstructing the passage of air
along the enclosed space; and that on the lower side being so fixed as to
exclude the external air in that direction. The top or roof shutters also
run into a groove along the ridge of the roof, and at the lower end fix
close down to the top of the side shutters, fastening with a button. Each
of the shutters should have a projecting fillet fixed on one side, so as
to shut close over the adjoining one. The shutters themselves should of
course be made of light frame-work, strengthened where necessary, with
small iron rods. The material used for covering them may be the asphalte
felt, now manufactured extensively for roofing purposes, or strong brown
paper, coated with tar; the latter is used extensively in Germany for this
purpose, and is found to be very durable and cheap; it is there even
preferred to every other material.

Though the covering of hot-houses has been already practised in some
cases, I am not aware of any one having adopted a close covering with the
view to facilitate ventilation or aëration during the night. It appears to
me that the circulation of air, secured by the means here proposed, would
have much influence in excluding cold, whilst at the same time it would
prevent the interior from becoming too warm and close.


_On Transplanting and the use of Turf Pots._

I have, at p. 26, given what appear to me to be some of the principal
reasons against the practice of transplanting, or planting out, Cucumber
and other plants. When this is done after any quantity of roots are
produced, some injury or check must be sustained during the process; and
checks of this kind are opposed to the realisation of the greatest results
within the shortest period, which of course is the great object in view.
Where it is inconvenient to plant the seeds in the places the plants are
intended to occupy, or to put out the young plants during the earliest
period of their development, or where propagation by cuttings or layers,
is adopted, and the plants of course have to be potted separately, so as
to be in a removable state, the following simple plan may be adopted, and
will be found to combine all the advantages and conveniences attending the
use of pots, with the avoidance of the evils of transplantation, &c. The
plan referred to, consists in the employment of turf or peat, so contrived
as to supply the place of pots, and which of course at the time of
planting is simply placed, along with the plant it contains, at once into
the soil, without in the least disturbing the roots, which, growing
through the substance of the turf, extend beyond it in all directions into
the free soil provided for them. These turf pots are made of spongy,
fibrous turf--whether loamy or peaty is not material, provided it is full
of fibre, so as to admit of being readily traversed by the roots. The
grassy surface is evenly removed, and the under-turves are cut three or
four inches in thickness, and are then divided into squares of about three
inches across. The centre of each of these little squares is taken out by
means of an iron scoop, such as that represented in the annexed sketch;
and this is then filled up with soil, and the plant, or seed, or cutting,
or layer, inserted as if it were into an ordinary flower pot. It will be
obvious that by this plan, every plant is independent and perfectly
removable--thus securing the convenience of sowing or planting and rearing
the plants in pots during their earliest stages: on the other hand, at the
time of planting out permanently, the plant, turf, and all being set
carefully into the soil, no check is sustained, because the roots remain
undisturbed, and may, as they advance, penetrate through the turf into the
prepared soil which surrounds them; in this way the advantages of sowing
or planting at the very first in the position the plants are intended to
occupy permanently, are secured.


[Illustration]


This plan of sowing seeds, or of planting young plants intended for
transplantation, into pots made of turf, is not only applicable to
cucumbers, but might be very extensively adopted in the case of annuals
and half hardy plants raised in frames, during the spring, in large
quantities for the flower garden. In these cases, however, as the quantity
that could be reared within a given space would be an object, the turves
should be as small as possible in their lateral dimensions--a bore of two
inches and a half, with half an inch on each side, thus making the
diameter three inches and a half, would be found convenient in this
respect. For cucumbers, however, or when the plan was applied to any
special object, a larger size might be employed, which would allow of the
plants attaining a larger size before it would be necessary to place them
in their permanent positions.


_On Watering the Soil._

In the diagram at p. 18, and the description of it at p. 20, I have
indicated and recommended a plan of moistening the soil by pouring water
down beneath the soil: this was to be done by the help of tubes provided
for the purpose. The soil was supposed to rest on the top of the hot
water-tank, which was to supply bottom heat; and immediately beneath the
soil, a layer of open rubble was proposed to be placed, among which the
water applied might find its way, and gradually moisten the superincumbent
soil. Mr. Hunter, gardener at Mawley Hall, in detailing[3] his sixteen
years' experience in tank-heating, has in great measure corroborated
these views; and as his corroboration of the plan I have recommended,
embodies some useful hints, I will quote the substance of his remarks:--"I
had a pit erected, thirty-eight feet long, seven and a half wide, divided
into four compartments, for growing melons and cucumbers, with a tank
extending the whole length of the pit, six feet wide and six inches deep.
Across this I put larch spars, and upon them turves, with the grassy side
downwards, and on them the soil for the melons and cucumbers. The plants
grew and did well for a time, but they were of short duration in
comparison with the dung-bed. Instead of the moisture ascending through
the soil as I expected, I found that the heat from the tank dried the
turves and soil next to them as dry as dust, and that there was no such
thing as obtaining a moist heat from hot water without the soil was in
contact with it. Next year I put broken stones upon the spars, and turves
upon them, and made my arrangements so that I could occasionally run water
in the tank to wet the turves and the soil next them. This was an
improvement; and I went on prosperously for some years, till the spars
began to decay. I then had iron bars put across, and two of the
compartments covered with squares, a foot in diameter, and one inch thick;
the other two with slates; both slates and squares jointed with Roman
cement, to prevent the soil from getting into the tank, as I had found the
inconvenience of it when using the spars. I put some broken stones upon
the covers, and turves upon them, and then the soil. Here my original
difficulty occurred; the soil next the covers got too dry, and to moisten
it from above was impracticable, without making the soil a complete
puddle, which would have stopped the healthy growth of the plants. To
remedy this, I put six small earthen pipes into each division, the one end
resting upon the tank covers, the other standing up above the soil. When I
found by the watch sticks that the soil was getting dry, I poured water
down the pipes through a tin funnel which I had made on purpose; this
spread itself over the surface of the tank covers, and diffused a gentle
moisture to the soil, so congenial to the growth of plants. This was a
move in the right direction. I then thought that it would be better to
pour the manure water down upon the tank covers, which I have done since.
I found the broken stones over the tank covers troublesome; they were also
a harbour for wood-lice. I now use only a layer of leaves next the covers,
and they are cleared out with the soil."


_On Atmospheric Humidity._

Cucumbers cannot at any time be successfully grown in an arid atmosphere,
although, during the winter season, they require a much less proportion of
atmospheric humidity, than under the influence of longer days and brighter
light; and conversely, the degree which would be necessary to secure their
welfare in summer, would be fatal to them in winter. An experienced
gardener would tell almost instinctively, at either season, whether a
sufficient supply was present or not; but less experienced cultivators
would need some index, or register, to guide them. Such an index is
afforded by the hygrometer; but most of the kinds of hygrometers are
delicate instruments, and hardly suited for garden use. What is needed in
this case is, not an instrument which requires minute observations and
calculations, but something that will at once indicate the atmospheric
humidity as plainly as the thermometer does the temperature, and which
may be as easily read off and understood. Simmons' hygrometer, recently
introduced to the notice of horticulturists, professes to supply this
desideratum; and though, perhaps, not a sufficiently accurate instrument
for purely scientific purposes, yet, as simply and clearly indicating what
is at least an approximation to the existing degree of atmospheric
humidity, it is to be regarded as a useful garden hygrometer. By it, the
degree of dryness or humidity is indicated on a dial-plate, by means of a
moveable arm resembling the hand of a clock. The dial-plate is marked off
into degrees, expressing the amount of moisture in the air, between what
is observed when the instrument is plunged in water on the one hand, and
exposed to excessive dryness on the other. As my own experience of this
instrument, though favourable to its use, is still but limited, I cannot
do better than introduce here the following remarks of Mr. Beck, of
Isleworth, a very successful cultivator of plants, and one who has had
considerable experience in the use of these instruments. It will be
observed that Mr. Beck's standard for the orchid-house will be about
suitable for cucumbers.[4] Mr. Beck observes,--"The skilful gardener,
observing the pointer to advance with dryness and return with moisture,
will soon form a standard for himself, by which to regulate his stove,
greenhouse, &c.; still some general scale is desirable. Two conditions
must be carefully observed:--1. The instrument must neither be hung in the
sun, nor where it will be liable to get wetted or saturated. 2. It must
not be subjected to greater heat than is suited to vegetable life. For the
six months commencing with August and ending with January, 40 deg. in,
the morning, increasing to 60 deg. about noon, and declining again to 40
deg. at night, is about the right scale for the orchid-house; whilst a
range from 50 deg. to 80 deg. would be suitable for both the stove and
greenhouse in those months. In the other half year, February and July
inclusive, 30 deg. to 40 deg., morning and evening, running up to 80 deg.
in the middle of the day for the orchid-house; 40 deg. and 50 deg., and up
to 70 deg. for the stove; and 50 deg. to 80 deg. for the greenhouse, will
prove very suitable. The above scale is desirable, but I do not say it is
always attainable. Ours is an uncertain climate; sometimes a dry east wind
will almost parch us up; at other times a southerly one, with wet, will
cause a superabundance, which will have to be corrected, possibly by a
gentle fire, and a free admission of air. The alteration hereby effected
in the atmosphere of the houses will soon be evidenced by the hygrometer,
and mildew and fogging off be kept at a distance. Opposed to an excess of
moisture in the dull months of the year, is the dryness consequent on the
summer and autumnal sunshine. Then, during the heat of the days, the
instrument will seem to have run wild. Throwing water on the floors of the
houses, and every means of increasing the amount of moisture, seems but of
little or temporary avail; Simmons will go up, spite of all, to 90 deg. or
100 deg., and none the worse either, for it is still a faithful indicator,
and as sure as the day declines, and the heat of the sun is withdrawn, so
will it come back to a suitable point, when the plants are watered and the
floors are wetted for the night. Remembering then, the variableness of our
climate, I candidly admit that I consider any precise directions of very
little value. None can be given that shall be implicitly followed, or on
which success shall certainly attend. Horticultural practice should be
made dependant upon ever-varying circumstances."

Mr. Belville, of the Royal Observatory, has constructed the following
Table, from a series of observations made with Simmons' hygrometer in
connexion with the dew point, as obtained by a Mason's hygrometer, or a
dry and wet thermometer.

  +------------------------------------------------------------------+
  |  Range            Mean   |                                       |
  |of Simmons'    Humidity of|                                       |
  |Hygrometer.       the Air.|                                       |
  +--------------------------|                                       |
  | 20° to  30°        1·00  |Extreme saturation; air precipitates   |
  |                          | moisture at a fall of temperature.    |
  | 30  ..  40         0·96  |                                       |
  | 40  ..  50         0·89  |                                       |
  | 50  ..  60         0·81  |                                       |
  | 60  ..  70         0·77  | }                                     |
  | 70  ..  80         0·72  | }Ordinary fine dry weather.           |
  | 80  ..  90         0·67  | }                                     |
  | 90  .. 100         0·59  |                                       |
  |100  .. 120         0·50  | Air contains one half of the moisture |
  |                          |  it is capable of holding in solution;|
  |                          |  in England very dry weather.         |
  +--------------------------+---------------------------------------+

     Example:--Suppose hygrometer read 45°, the mean humidity
     corresponding is 93. Again, if hygrometer read 90°, the mean humidity
     corresponding is 59°.


_Mushrooms._ (See p. 22.)

Convenience for growing mushrooms may always be planned in a cucumber
house; and as these excellent fungi are universally approved, it may be
useful to append an epitome of the mode in which they should be
cultivated.

The best, or, at least, most convenient situation for the bed, would be
beneath that provided for the cucumber plants (see p. 18). The front may
be formed of two course of brick-on-edge, and if divisions are required,
they should be formed in the same way. The bottom should be made even, and
rendered dry. The material for forming the bed itself consists of short
stable litter, with horse-droppings, but chiefly the latter, brought to a
certain state of fermentation. The droppings and litter should be obtained
daily from the stable, until enough for a bed is collected; it should,
from day to day, be thrown up into a flattish heap, in a dry place, where
it will ferment very slightly. As soon as enough is got together to begin
to ferment, the heap must be turned over; and in these turnings, the outer
and inner parts of the heap, as well as the fresh and the fermenting, must
be well mixed up together; the heaps should be turned every second day,
and should never be made large, or else the dung would become both too hot
and too dry, either of which would spoil it. To avoid this, the heaps
should be flat and shallow, with as much outside as possible; in this way
the air, acting on a considerable portion of it, renders it rather dry,
and checks too rapid fermentation. This preparation must be continued
until the whole mass is brought to an uniform mild, dryish state of
fermentation. Then the bed may be made in the following manner:--About
three inches of the prepared dung is laid evenly over the bottom, and is
beaten down firmly with a flat heavy wooden mallet. Another layer is then
put on in the same way, and this is repeated until the bed is formed to a
thickness of about six inches. The next two inches of the dung should have
about a sixth part of light turfy loam reduced to mould, and sifted, mixed
with it to give it body. The bed is now prepared, and is to be spawned as
soon as it is seen that it does not heat violently. The heat ought not to
exceed 90 degrees: if it reaches higher than this, holes must be made, a
few inches apart, to let the heat pass off, and in a day or two these may
be filled up again. The spawn is to be put in when the heat ranges about
75 degrees; lumps of spawn about as large as a small egg may be used; a
hole should be made with the fingers about two inches deep, the spawn
inserted, and the material of the bed closed about it. Probably by this
time there will be no danger of overheating, and if so, the soil may be
put on; if, however, there is any inclination to overheat, wait till it
has passed off before putting on the soil. The soil used should be
decomposed turfy loam, moderately dry, so as to bear compression without
running together like paste, but damp enough to become firm, close, and
even, when beaten closely. About two inches in thickness should be put on,
and this is to be beaten down quite firm and close. The beds are then
finished. It is as well to cover the surface with a thin layer of short
hay, to prevent it becoming quite dry. Mushroom beds seldom require water;
after they have been some time in bearing, the beds sometimes get dry, and
in such cases, if they have a moderate soaking of _tepid_ water, and the
surface is covered as before, a new crop will spring up. The covering is
best removed when the beds are in bearing. It is seldom advisable to apply
water when the beds are coming into bearing. Water should never be used in
any other than a tepid state.

Mushrooms are most prized in the summer, though the atmosphere of a
cucumber-house would not then be suitable for them, unless the space about
them could be closed in, so as to retain a close, somewhat humid
atmosphere. They would succeed very well without being enclosed, during
the season for forcing cucumbers.

Under the treatment which has been detailed, the beds would usually come
into bearing in about six weeks from the time of spawning; and, under
favourable circumstances, would continue in bearing for two or three
months.




Footnotes:

[1] The Journal of the Horticultural Society of London, vol. I. p. 114.

[2] Ib. vol. II. p. 29.

[3] Gardener's Journal, 1847, p. 339.

[4] Gardener's Chronicle 1847.




Transcriber's Notes:

Passages in italics are indicated by _underscore_.

The following misprints have been corrected:
  "influenee" corrected to "influence" (page 21)
  "circumstauces" corrected to "circumstances" (page 32)
  "analagous" corrected to "analogous" (page 36)
  "shonld" corrected to "should" (page 36)
  "distributiug" corrected to "distributing" (page 40)
  "appropaiated" corrected to "appropriated" (page 55)
  "conditious" corrected to "conditions" (page 72)

Other than the corrections listed above, printer's inconsistencies in
spelling and hyphenation usage have been retained.

Punctuation has been corrected without note.