Soil for Bulbous Plants.
Comparatively few of the bulbous plants mentioned in this volume will require anything better than ordinary good garden soil that has been deeply dug, contains a certain amount of well-decomposed manure, and is well-drained so that the water freely passes away. Such a soil will give general satisfaction, with the least amount of trouble, especially if it is inclined to be light rather than heavy.
To secure really first-class results, however, the soil in beds or borders that are to be planted with bulbs should be particularly well-prepared in advance. A heavy soil, that is, one inclined to hold water, and of a clayey nature, will require a good deal more labour to bring it into a proper condition than a soil that is already friable and in a fair state of tilth. The heavy soil should be not only deeply dug to a depth of two feet or more, taking care not to bring the lower layers to the surface in the operation, although they should be turned over and pulverised as much as possible where they are. Plenty of sand or road-grit should be incorporated with a heavy soil, not only to keep it "open," but also to increase its warmth—a matter of some importance in our cold wet winters. The upper layer of soil, say a foot from the surface, may be still further improved by the admixture of old cow-manure and soot. In very bad soils, powdered quicklime may also be added, not only to absorb superfluous moisture, but to render the soil sweeter and more fertile. On no account, however, should fresh, rank manure be dug into the soil just before the bulbs are planted, as the heat and gases generated by its decomposition are often injurious to the extremely tender tips of the young roots.
An ordinary good garden soil—that is, one that is regularly dug, hoed, manured, and cropped with some class of plants—will only need to be well dug for bulbs, and to have some well-decayed manure and soot incorporated with it a week or two before planting. For some bulbs, such as the Mariposa Lilies (Calochorti), some of the bulbous Irises, and a few other kinds, it may be necessary to take particular pains with the preparation of the soil for them. Attention has been specially called to plants of this nature, where such has been considered necessary. It should be remembered that when bulbous plants are attacked by fungoid diseases, referred to at p. 145, it is very often the result of a badly prepared soil, and not to any inherent defect in the bulbs.