Instructions in gardening for ladies

by Mrs. Loudon

The reasons for the second and third points of covering the seeds, and yet not covering them too deeply, appear more obvious; and yet they also require a little explanation. The seeds are covered to keep them in darkness, and to retain round them a proper quantity of moisture; not only to make them swell and begin to vegetate, but to enable the roots to perform their proper functions; since, if exposed to the air, they would become dry and withered, and lose the power of contracting and dilating, which is essential to enable them to imbibe and digest their food. Burying the seeds too deeply is obviously injurious in impeding the progress of the young shoot to the light; and in placing it in an unnatural position. When a seed vegetates too far below the surface, a part of the stem of the plant must be buried; and this part not being intended to remain under-ground, is not protected from the dangers it is likely to meet with there. It is thus peculiarly liable to be assailed by slugs and all kinds of insects, and to become rotten by damp, or withered by heat. It is also very possible to bury a seed so deeply as to prevent it from vegetating at all. The ground has more of both warmth and moisture near the surface than at a great depth, as it is warmed by the rays of the sun, and moistened by the rain; but besides this, seeds will not vegetate, even when they are amply supplied with heat and moisture, if they are excluded from the influence of the air. Every ripe seed in a dry state is a concentration of carbon, which, when dissolved by moisture, and its particles set in motion by heat, is in a fit state to combine with the oxygen in the atmosphere, and thus to form the carbonic acid gas which is the nourishment of the expanding plant. For this reason, seeds, and newly sprung-up plants do not want to be supplied with manure, and air is much more essential to them: they have enough carbon in their cotyledons or seed-leaves, and they only want oxygen to combine with it, to enable them to develope their other leaves; and this is the reason why young plants, raised on a hotbed, are always given air, or they become yellow and withered. Light absorbs the oxygen from plants, and occasions a deposition of the carbon. Thus seeds and seedlings do not require much light; it is indeed injurious to them, as it undoes in some degree what the air has been doing for them: but young plants, when they have expanded two or three pairs of leaves, and when the stock of carbon contained in their cotyledons, or seed-leaves, is exhausted, require light to enable them to elaborate their sap, without which the process of vegetation could not go on. Abundance of light also is favourable to the development of flowers, and the ripening of seeds; as it aids the concentration of carbon, which they require to make them fertile. The curious fact that seeds, though abundantly supplied with warmth and moisture, will not vegetate without the assistance of the air, was lately verified in Italy; where the Po, having overflowed its banks near Mantua, deposited a great quantity of mud on some meadows; and from this mud sprang up a plentiful crop of black poplars, no doubt from seeds that had fallen into the river from a row of trees of that kind, which had formerly grown on its banks, but which had been cut down many years previously. Another instance occurred in the case of some raspberry seeds found in the body of an ancient Briton discovered in a tumulus in Dorsetshire. Some of these seeds were sown in the London Horticultural Society’s Garden at Turnham Green, where they vegetated, and the plants produced from them are still (1839) growing. Numerous other nearly similar instances, will be found in Jesse’s Gleanings, Hooker’s Botanical Miscellany, and numerous other works. Steeping seeds in oxalic acid, &c. to make them vegetate, is efficacious; as there is a speedier combination between the carbon in the seeds, and the oxygen in the acid, than can be effected by the ordinary agency of the air in parting with its oxygen to them.

Planting bulbs and tubers bears considerable analogy to sowing seeds. The bulb or tuber may indeed be considered as only a seed of larger growth, since it requires the combined influence of air, warmth, and moisture to make it vegetate, and then it throws out a stem, leaves, and roots like a seed. There is, however, one important difference between them; the seed expends its accumulated stock of carbon in giving birth to the root, stem, and leaves, after which it withers away and disappears; while the bulb or tuber continues to exist during the whole life of the plant, and appears to contain a reservoir of carbon, which it only parts with slowly, and as circumstances may require. Though bulbs and tubers have here been mentioned as almost synonymous, modern botanists make several distinctions between them. The tunicated bulbs, such as those of the hyacinth and the onion, and the squamose bulbs, such as those of the lily, they consider to be underground buds; while tubers such as those of the dahlia, and the potatoe, and solid bulbs or corms, such as those of the crocus, they regard as underground stems.

These distinctions, however, though they may be interesting to the botanist and vegetable physiologist, are of little or no use in practice; the practical gardener treating bulbs and tubers exactly alike, and planting them as he would sow a seed: that is to say, he fixes them firmly in the ground, and covers them, but not so deeply as to exclude the air. In preparing a bed for hyacinths or other tunicated bulbs, it is necessary to pulverize the soil to a much greater depth than for ordinary seeds; as the fibrous roots of the hyacinth descend perpendicularly to a considerable depth, as may be seen when these plants are grown in glasses. The very circumstance of growing hyacinths in glasses, where they vegetate and send down their roots exposed to the full influence of the light, appears contrary to the usual effects of light on vegetation; and indeed the plants are said generally to thrive best, when the glasses are kept in the dark till the roots are half grown. However this may be, it is quite certain that hyacinths in glasses should never be kept in darkness when their leaves begin to expand; as, if there be not abundance of light to occasion rapid evaporation from the leaves, the plants will soon become surcharged with moisture from the quantity constantly supplied to their roots; and the leaves will turn yellow, and look flaccid, and unhealthy, while the flowers will be stunted, or will fall off without expanding.

Transplanting.—The points to be attended to in transplanting, are—care in taking up, to avoid injuring the spongioles of the roots; planting firmly to enable the plant to take a secure hold of the soil; shading to prevent the evaporation from the leaves from being greater than the plant in its enfeebled state can support; and watering that it may be abundantly supplied with food in its new abode. The first point is to avoid injuring the roots, and it is only necessary to consider the construction and uses of these most important organs to perceive how impossible it is for the plant to thrive, unless they are in a perfectly healthy state. Roots generally consist of two parts; the main roots which are intended to act as grappling irons to enable the plants to take a firm hold of the ground, and the fibrous roots which are intended to supply the plant with nourishment. These fibrous roots are most liable to receive injury from transplanting, as they are covered with a very fine cellular integument, so delicate in its texture as to be very easily bruised; and they each terminate in a number of small pores of extraordinary delicacy and susceptibility, which act as little sponges to imbibe moisture for the use of the plant. It is well known that these spongioles are the only means which the plant possesses of imbibing food, and that if they should be all cut off, the plant must provide itself with others, or perish for want of nourishment. These spongioles are exactly of the nature of a sponge; they expand at the approach of moisture, and when surcharged with it, they contract, and thus force it into the fibrous roots, the cellular integument of which dilates to receive it; hence the moisture is forced, by capillary attraction, as it is supposed, into the main roots, and thence into the stem and branches of the plant; circulating like the blood, and after it has been elaborated in the leaves, as the blood is in the lungs, dispensing nourishment to every part as it goes along.

The roots have no pores but those forming the spongioles; and only the fibrous roots appear to possess the power of alternate dilation and contraction, which power evidently depends on their cellular tissue being in an entire and healthy state. Thus, it is quite evident that if the spongiole of any fibril be crushed, or even the cellular tissue injured, it can no longer act as a mouth and throat to convey food to the plant. When this is the case, the injured part should be instantly removed; as its elasticity can never be restored, and it is much better for the plant to be forced to throw out a new fibril, than to be obliged to carry on its circulation weakly and imperfectly with a diseased one. Whenever a plant is taken up for transplanting, its roots should therefore be carefully examined, and all their injured parts cut off, before it is replaced in the ground. Deciduous plants, and particularly trees and shrubs, are generally transplanted when they are without their leaves; because at that season they are in no danger of suffering from the effects of evaporation.

Shading is necessary after transplanting all plants that retain their leaves; as the evaporation from the leaves, if exposed to the full action of the light, would be greater than the plant could support with a diminished number of spongioles. If it were possible to transplant without injuring the fibrils, and if the plant were immediately supplied with plenty of water, shading would not be required; and, indeed, when plants are turned out of a pot into the open garden without breaking the ball of earth round their roots, they are never shaded. The reason for this is, that as long as a plant remains where it was first sown, and under favourable circumstances, the evaporation from its leaves is exactly adapted to its powers of absorbing moisture; it is therefore evident, that if, by any chance, the number of its mouths be diminished, the evaporation from its leaves should be checked also, till the means of supplying a more abundant evaporation are restored.

The use of watering a transplanted plant, is as obvious as that of shading. It is simply to supply the spongioles with an abundance of food, that the increased quantity imbibed by each, may, in some degree, supply their diminished number.

All plants will not bear transplanting, and those that have tap-roots, such as the carrot, are peculiarly unfitted for it. When plants having tap-roots are transplanted, it should be into very light soil, and what is called a puddle should be made to receive them. To do this, a hole or pit should be formed, deeper than the root of the plant, and into this pit water should be poured and earth thrown in and stirred so as to half-fill it with mud. The tap-rooted plant should then be plunged into the mud, shaking it a little so as to let the mud penetrate among its fibrous roots, and the hole should be filled in with light soil. The plant must afterwards be shaded longer than is usual with other plants; and when water is given, it should be poured down nearer to the main root than in other cases, as the lateral fibrous roots never spread far from it. Plants with spreading roots, when transplanted, should have the pit intended to receive them made shallow, but very wide in its diameter; so that the roots may be spread out in it to their fullest extent, except those that appear at all bruised or injured, which, as before directed, should be cut off with a sharp knife.

It is a general rule, in transplanting, never to bury the collar of a plant; though this rule has some exceptions in the case of annuals. Some of these, such as balsams, send out roots from the stem above the collar; and these plants are always very much improved by transplanting. Others, the fibrous roots of which are long and descending, such as hyacinths, bear transplanting very ill, and when it is absolutely necessary to remove them, it should be done with an instrument called a transplanter; which may be purchased in any ironmonger’s shop, and the use of which is to take up a sufficient quantity of earth with the plant to remove it without disturbing the roots.

The uses of transplanting are various. When seeds are sown, and the young plants from them begin to make their appearance, they will generally be found to be much too thick; and they will require thinning, either by drawing some of them out and throwing them away, or by removing them to another bed by transplanting. This, in the case of annuals, is called by the gardeners pricking out. The young plants are taken up with a small trowel, and replaced in a hole made for them, and the earth pressed round them, with the same trowel; the only care necessary being to make them firm at the root, and yet to avoid injuring the tender spongioles. Gardeners do this with a dibber, which they hold in the right hand, and after putting in the young plant with the left hand, they press the earth round it with the dibber in a manner that I never could manage to imitate. I have found the trowel, however, do equally well, though it takes up rather more time.