BULBS

The term "bulb" is used by most people to refer to plants that have underground, fleshy storage structures. Only some of the plants commonly called bulbsactually are bulbs. The definition of a bulb is any plant that storesits complete life cycle in an underground storage structure.

The primary function of these underground storage structures is to storenutrient reserves to ensure the plants' survival.

Bulbs or bulb-like plants are usually perennials. They have a periodof growth and flowering. This is followed by a period of dormancy where they die back to ground level at the end of each growing season. For springbulbs, the end of the growing season is in late spring or early summer. Spring bulbs start to grow again in the fall and flower the followinggrowing season.

Bulbs can be broken down into five types of storage structures. Theseinclude: true bulbs, corms, tubers, tuberous roots and rhizomes. A sixth category of fleshy roots has been added here for the purpose of showingthe structure. Daylilies and peonies, which are popular plants with gardeners, are examples of this type.

TrueBulbs

The true bulb has five major parts. It contains the basal plate (bottomof bulb from which roots grow), fleshy scales (primary storage tissue),tunic (skin-like covering that protects the fleshy scales), the shoot(consisting of developing flower and leaf buds), and lateral buds (developinto bulblets or offsets).

True bulbs are divided into tunicate bulbs and imbricate bulbs. A tunicatebulb has a paper-like covering or tunic that protects the scales from drying and from mechanical injury.

Good examples of tunicate bulbs include: tulips, daffodils, hyacinths, grape hyacinths (muscari), and alliums.

Many plants such as daffodils form new bulbs around the original bulb. These bulbs, called offsets, develop from buds within the base of themother bulb and produce new plants. When these bulbs become overcrowded,the flowers start to diminish in size. This is an indication that it istime to dig up and divide the bulbs.

An example of the imbricate bulb is the lily. The imbricate bulb does not have the tunic (papery covering) to protect the fleshy scales.

Imbricate bulbs must be kept constantly moist before planting so they are not injured by the scales drying out.

Lilies can be propagated from bulbils that develop in the leaf axils of the plant. They can also be propagated from bulblets that develop at the base of fleshy lily scales if maintained in a moist sand medium. Itwill take more than one year for the bulbils or bulblets to become flower size.