Growth of a Corm.—The vegetation of the corm is very remarkable, and somewhat resembles that of the Tulip. When a corm commences to grow, the reserve material within it is used up for the benefit of the flowers and leaves. The result of this absorbing process is that by the end of the season the old corm has almost vanished, or is reduced to a dry shrivelled, woody, and lifeless mass, incapable of further growth, and attached to the base of the new corms, as shown in the annexed sketches of Gladiolus and Crocus on [page 14].
These new corms are the direct result of the work that has been done by the green leaves in the daylight, and after a period of rest, they go through precisely the same process the following season—vanishing themselves, but leaving others behind to carry on the work of producing flowers, and, if possible, seeds.
| Gladiolus. o. c. old corm; c. r. contractile roots; n. c. new corms with "spawn" (s.) at base. | Crocus Corm. o. c. old corm; n. c. new corm with growths. |
The [importance of Green Leaves] to Bulbs and Corms. —If the reader wishes to be successful in growing bulbous plants in his garden he must have very great respect for the green leaves of his plants, and always endeavour to keep them in the cleanest and healthiest possible condition. From what has just been said about the production of new bulbs in the Tulip, and new corms in the Crocus and Gladiolus, it is obvious that the leaves play a most important part. Indeed, without their aid there would be neither bulbs nor corms to carry on the work of the plants from year to year. In the form of carbon-dioxide the leaves eat up the carbon and oxygen from the atmosphere. Under the influence of sunlight the gas is decomposed, so that the oxygen is given off again into the air, while the carbon is retained for the production of starch and other materials. These are elaborated in the cells of the leaves, and after undergoing certain changes pass down the stems and are stored up in the bulbs or corms beneath the surface of the soil. It is only green healthy leaves that can perform this important work satisfactorily. When the foliage therefore begins to turn yellow and wither, it may be taken for granted that its work for the season is coming to a close, and the bulbs or corms are going to enjoy a well-earned rest. It should, perhaps, be mentioned also that leaves can only become green in day light; and although some bulbous plants like a certain amount of shade, it would never do to exclude the light from them altogether, or even to plant them in places where they could not get an adequate amount of sunshine, or diffused light, during the day.
[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.