Plant Propagation Technique
A Bulb is formed upon or beneath the ground, and is a swollen stock, consisting, in the first place, of a more or less fleshy disk, which below gives rise to the roots; secondly, of more or less fleshy coats, or scales, originating on the disk; thirdly, of a more or less central shoot, equally borne by the disk, protected by the coats or scales already mentioned, and formed of immature leaves and flowers.
In some instances, small Bulbs, called Cloves, are formed at the base of the scales of the original Bulbs; these are destined to reproduce the plant. Shallot and Garlic are good examples. Bulbs are, in fact, warehouses, storing the strength and energy acquired by the plant during the current season, for the demands of the next. They are classified under two sections - Scaly and Tunicated. In the former, the scales of the Bulb overlap each other like roof shingles, as in the Lily; in the latter, they form continuous coatings, one within the other, as in the Hyacinth. In several Lilies, young Bulbs are found growing in the axils of the leaves, when they are known as Bulbils.
Bulbs are commonly imported from Holland, giving rise to the formerly popular term of Dutch Flower Roots, mostly planted in North America during the fall for spring flowering.
Crocus, Cochicum, Cyclamen, Gladiolus, and several others, are not Bulbs, but Corms.
The flowering season varies according to the different types of Bulbs. The majority may be lifted from the soil and kept tolerably dry during the resting period; but they wither and become exhausted if not replanted at the proper time, thereby causing many failures. Bulbs are generally available at nurseries and garden centers in September, and the best results are obtained from home potting or planting at once, although some for succession may be kept in reserve up until the beginning of November.
The failure of many in cultivating imported Liliums and other Bulbs is often be caused by their long-continued confinement in a dry atmosphere, whereby their vitality is often almost lost. The roots of some bulbs are nearly always, more or less, in action, and these, especially, should not be kept out of the ground for any appreciable length of time.
Bulbs should be planted upright, with the pointed end facing towards the sky, and at the recommended planting depth for that particular variety. In most cases, a Bulb should be planted about three times as deep as the Bulb's greatest diameter. Larger Bulbs should be planted between four and six inches apart, while smaller Bulbs should be placed between one and two inches apart.
In the spring, when leaves are emerging, fertilize sparingly with a fertilizer formulated specifically for Bulbs.
When bulbs begin crowding each other out, indicated primarily by the production of fewer and smaller blooms, you may divide the bulbs to produce even more plants. Generally speaking, division may be undertaken every two to three years, ideally when the leaves have begun to yellow. You should immediately replant the divisions.
Plant Propagation by Bulb Articles
Fall Storage of Tender Bulbs, Corms & Tubers
By Sherry Rindels, Department of Horticulture
Iowa State University, Ames, Iowa.
Planting Depth and Spacing of Bulbs
By Richard Jauron, Department of Horticulture
Iowan State University, Ames, Iowa
Time To Plant The Bulbs