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.