Instructions in gardening for ladies

by Mrs. Loudon

All soil, to be in a fit state for growing plants, should be sufficiently loose and dry to allow of water passing through it intermixed with air; as water, when in this state is never more than slightly impregnated with the nutritious juices of the manure through which it has passed. The spongioles are thus not supplied with more food at a time than they can properly take up and digest, and a healthy circulation of the fluids is kept up through the whole plant. But, what, it may be asked, is to be done with a garden, the soil of which has become black and slimy like half-rotten peat? The quickest remedy is covering it with lime, as that combines readily with the humic acid, and reduces it to a state of comparative dryness: or, if the sub-soil be good, the ground may be trenched, and the surface-soil buried two spits deep; in either case it will be necessary thoroughly to drain the garden to prevent a recurrence of the evil.

All the different kinds of soil found on level ground, consist of two parts, which are called the surface-soil and the sub-soil; and as the sub-soil always consists of one of the three primitive earths, so do these earths always enter, more or less, into the composition of every kind of surface-soil. The primitive earths are—silex, (which includes sand and gravel,) clay, and lime, which includes also chalk; and most sub-soils consist of a solid bed or rock of one or other of these materials, probably in nearly the same state as it was left by the deluge. The surface-soils, on the contrary, are of comparatively recent date; and they have been slowly formed by the gradual crumbling of the sub-soil, and its inter-mixture with decayed animal and vegetable matter, and with other soils which may have been accidentally washed down upon, or purposely brought to it. In fields, and uncultivated places, the surface-soil is almost as hard, and as coarse in its texture, as the sub-soil on which it rests; but in gardens which have been long in cultivation, the surface-soil becomes so thoroughly pulverized by frequent diggings, and so mixed with the manure and decayed vegetables which have been added to it from time to time, that it is changed into the soft, light, fine, powdery substance, called garden-mould. If the sub-soil be naturally porous or well drained, this mould, however rich it may be made by the addition of decayed vegetable matter or animal manure, will always continue friable; and as long as it does so, it will be fit for the growth of plants: but if no vent be allowed for the escape of the water, and it be continually enriched with manure, it will be changed in time into the black slimy substance that has been already described.

Surface-soil is called peat-earth when it is composed of decayed vegetable matter, without any mixture of animal manure; and, as this excess of vegetable matter could neither be produced nor decayed, without abundance of stagnant moisture, this kind of earth is almost always found on a clayey sub-soil, which prevents the water which falls upon it from escaping. Peat-earth has a spongy, elastic feeling when trodden upon, arising from the quantity of water that it holds, and it can only be rendered fit for cultivation by draining. In its elastic state it is what is called in Scotland a moss, and in England a peat-bog. Should the water, instead of being afforded a vent by drainage, be suffered to accumulate for many years, till it completely saturates the peat, the soil becomes what is called a morass, or quagmire; and it can no longer be trodden on, as it will engulf any substance resting upon it. A still further accumulation of water will, in the course of years, cause the bog to burst its bounds, and overflow the surrounding country; as the Solway-moss did many years ago, and as bogs in Ireland have done frequently. An excess of vegetable matter on a silicious sub-soil, differs from the common black-peat in retaining less water; and in being mixed with a portion of the primitive earth, which, from its loose texture, becomes easily detached from the sub-soil. Peat in this state is called heath mould.

The most productive soils are those in which several ingredients are combined in proper proportions; and if any one of the primitive earths preponderates, the soil becomes comparatively unfertile. Thus the best soil for gardening purposes is generally allowed to be a calcareous loam on a chalky sub-soil; and this sort of soil is composed of nearly equal parts of lime, sand, and clay, enriched depositions of decayed animal and vegetable matter. The next best soil is a sandy loam, composed of clay and sand, enriched by decayed animal and vegetable substances, and resting on a sandy or gravelly sub-soil. The worst soils are peat and sand. A poor sandy soil is necessarily a nearly barren one; because it will not retain either water, or the nutritious juices from manure, long enough to afford nourishment to the plants grown upon it; and it is obvious that a soil of this kind can only be rendered fertile by mixing it with clay; which would change it into a sandy loam.

A stiff clay is unfertile from its attracting moisture and retaining it round the roots of the plants till they become swollen and unhealthy. It also retards the decomposition of manure, and obstructs the progress of the roots, which waste their strength in the efforts they make to penetrate, or twine round, its adhesive clods. Soils of this description are improved by a mixture of sand, gravel, road grit, or any substance which tends to separate the particles of the clay, and to render it light and friable.

Chalky soils succeed better unmixed, than any of the other kinds; but chalk being a carbonate of lime, can hardly be called a primitive soil. The chalk, however, from its whiteness is colder than any other soil; as it does not absorb, but reflects back the rays of the sun. Rain also penetrates into it very slowly, and not to any great depth. Chalk mixed with sand forms a kind of calcareous loam admirably adapted for growing vegetables; and chalky soils are peculiarly susceptible of improvement from manure.

Manures.—The kinds of manure generally used in gardens are horse or cow dung, and decayed vegetable matters; the manure in both cases being suffered to lie in a heap to rot before it is spread on the ground, in order that its component parts may be decomposed by fermentation, and thus brought into a fit state to afford food to the plants. Old hot-beds or mushroom beds are thus well adapted for manuring a garden; and when fresh stable-dung is employed for that purpose, it is generally thrown into a heap, and turned over several times till the fermentation has abated, before it is dug into the ground. As, however, a great quantity of carbonic acid gas is evolved and escapes during the process of fermentation, and as it seems a great pity that so much of the nutritious properties of the manure should be lost, it is now customary to cover the dunghill with earth, into which the gases will rise during the process of fermentation, and in which they will deposit the greater part of their nutritious properties. A quantity of earth should also be laid round the dunghill to imbibe the liquid that runs from it, and this earth, part of which must be removed and fresh added every time the dunghill is turned over, will be found very nearly as valuable for manuring the beds of a garden, as the manure itself.

The modes of applying manure differ according to the difference of the soils. For sandy loams, thoroughly rotten dung, either from an old hotbed, or from a dunghill sufficiently decayed to be cut easily with the spade, or the earth that has covered a dunghill during the process of fermentation, should be laid on the surface of the soil, and dug in. In very poor sandy soils rotten manure, or earth from a dunghill, should be laid on the surface of the soil, and not dug in: being covered, if hot dry weather be expected, with leaves, straw, or the branches of trees cut off in pruning; or occasionally sprinkled with water. Soils of this description, and loose sands, are frequently improved in the South of France and Italy, by sowing them with seeds of the common white lupine, and then, when the plants have come up and grown about a foot high, ploughing or digging them into the soil. The green succulent stems of the lupines, when thus buried in the soil, supply it with moisture during the process of their decay; and thus nourishment is afforded to the corn, which is immediately afterwards sown upon the soil for a crop. Clayey soils should have unfermented manure mixed with undecayed straw laid in the bottom of the furrows made in digging; that the process of fermentation, and the remains of the straw may operate in keeping the particles of the soil open, or, in other words, in preventing their too close adhesion. Lime (though when burnt it becomes violently caustic, and will destroy and waste all the manure applied with it), as carbonate of lime, or chalk (in which state only it can properly be called a soil), retains the manure applied to it longer than any other soil. Rotten manure may thus be dug into chalk, with the certainty that it will be preserved from farther decay for a very long time, and that every shower will work a small portion of its fertilizing juices out of it, and carry them into the soil, where they will be thus presented to the plants in the best possible state for affording wholesome food.

Peat soils may be improved by the addition of quick-lime as a manure, which will absorb the superabundant moisture which they contain; or they may be mixed with sand, gravel, or clay to give them firmness and tenacity, and then with a small quantity of animal manure. Sandy peat or heath mould is very useful in gardens for growing heaths, rhododendrons, kalmias, or any plants with fine hair-like roots; and from the quantity of vegetable matter that it contains naturally, it does not require any manure, more than what is furnished by the decaying leaves of the plants grown in it.

Nearly the same rules apply to decaying leaves and other substances used as manure, as to stable-dung. They may be buried in an undecayed state in clayey soil, when it is the object to separate the adhesive particles of the clay by the process of fermentation; but their component parts should be separated by fermentation before they are applied as a manure to growing plants. Vegetable mould (that is, leaves thoroughly decayed and mixed with a little rich loam) is admirably adapted for manuring the finer kinds of flowers, and plants in pots. There are many other kinds of manure used in gardens occasionally; such as the dung of pigs, rabbits and poultry, grass mown from lawns, parings of leather, horn shavings, bones, the sweeping of streets, the emptying of privies, cess-pools, and sewers, the clipping of hedges and pruning of trees, weeds, the refuse of vegetables, pea halm, &c. All these should be fermented, and applied, in the same manner as the common kinds of manure.