Very few gardeners can be said to make anything[89][90] approaching adequate use of the soil which they cultivate. The majority of amateur gardeners, and not a few professional ones, never get their spade more than a foot or, at the outside, more than eighteen inches below the surface. As a matter of fact, all garden soil should be dug to a minimum depth of two feet, or preferably to a depth of three feet when possible. In preparing a piece of ground for planting, it should, therefore, be trenched as deeply as possible, preferably to a depth of three feet.
This operation may be performed as follows:—
Let A B C D represent the piece of ground to be trenched. Measure off A E, E G, G M, D F, F H, and N H, each the distance of one foot. Stretch a line from E to F and notch the surface with a spade along this line. Proceed in the same way from G to H. Next dig the piece A E F D to a depth of one foot, wheeling this surface soil to form a heap at B. Also dig to the same depth the piece E G H F and add this soil to the heap at B. Next remove the subsoil from the piece A E F D to the depth of another foot, and wheel it to C. The deeper subsoil in the piece A E F D should then be dug to a depth of another foot and left in its old position. The subsoil from E G H F to the depth of a foot should now be placed with the spade on A E F D, and the deep subsoil below it dug and left in situ. A layer of farm-yard manure may next be placed on the A E F D, and on this should be placed the top foot of soil from G M N H. The subsoil from G M N H should next be placed on E G H F, on this being placed a layer of manure covered in turn by fresh top soil. In this the work should be proceeded with until the last two feet of the patch are reached. The subsoil from I B C J is to be placed on the deep subsoil of K I J L, on this a layer of manure covered by one half of the surface soil in the heap at B. The heap of subsoil at C and the remainder of the surface soil at B are to be placed in the space I B C L.
This proceeding may strike the novice much as a problem of Euclid strikes the mentally lazy, but the importance of deep cultivation is so great that everyone who would be a successful gardener should thoroughly understand its practice. By the method of trenching above described, the three layers of earth called here soil, subsoil and deep subsoil are maintained in their respective orders of depth, for nothing is more fatal than to bury the "living earth" of the surface below the reach of the roots of our plants, bringing to the surface in its place the barren subsoil devoid of humus and devoid of those living bacteria so essential to the fertility of the soil. By proper and continuous cultivation, the actual living soil attains an ever increasing thickness, so that in time the top two feet may be correctly described as surface soil and become freely interchangeable throughout its thickness.
[MANURES]
The idyll of manures has been written by the Dean of Rochester, who has placed on eternal record his devotion to Sterculus, the son of Faunus, whom he imaged as riding proudly, pitch-fork ("agricultural trident") in hand, in his family chariot, the currus Stercorosus (Anglice, muck-cart). As I can confess to no such love, I will merely state the few facts which all plant-growers must bear in memory.
The great and safe manure for hardy flower culture is that of the stable or farm-yard, which is so valuable, not only for the actual food elements which itself contains, but also for the mass of straw and other organic material which by its fermentation sets up chemical activity in the soil, and so liberates a small continuous supply of the plant-foods therein contained. This latter property is what gives much of its manurial value to the mixed "rubbish" of the ash-pit—containing as it generally does such waste organic matter as cabbage leaves, potato-peelings, and "bits" of all kinds. Buried weeds, leaves and "garden refuse" act in a precisely similar way. These organic manures are, moreover, of the greatest service in keeping the soil open, porous and friable, in retaining water and so retaining also mineral plant-foods dissolved therein, and in adding to the warmth of the soil both by engendering heat in the process of fermentation and by mechanically rendering the soil a worse conductor.