Bulbs, Rhizomes, Tubers, Corms

Bulb (tulip)	Rhizome (iris)	Tuber (Jerusalem artichoke)	Corm (gladiolus)

Bulbs, corms, rhizomes, and tubers should be dug and divided in early spring, or in the fall when the plants are dormant. The nutrients that are needed to provide the next years flowers, develop through energy which the leaves absorb after the flowers are spent. For this reason it is best to remove the dead blooms and then leave the plant alone until the foliage dies back naturally.

* Bulbs are the thickened underground storage organ of the group of perennials which includes daffodils and tulips.
* Tubers are flat underground stems which store food and plant energy and from which a plant grows. (e.g. Dahlias)
* Corms are thick underground stems which produce the new roots, leaves and flowers during each growing season.
* A Rhizome is a modified plant stem which grows horizontally under the surface of the soil. New growth then emerges from different points of the rhizome. Irises and some lawn grasses are rhizomatous plants.