Tuesday, August 11, 2009
The Difference between Bulbs and Corms
Oriental Lilies grow from a bulb.
The nutshell difference between corms and bulbs is that corms are solid and bulbs have layers of scales.
Bulbs reproduce by dividing. Corms form a new corm on top the old -- gladioli are a great example -- and the old corm dries up.
Crocosmia not only forms a new corm, but sends out stolons on which more little cormels form. Bulbs sometimes form bulbils on the stem. Those little bulbils and cormels can be planted up to make more plants, fun.
Crocosmia, gladioli and crocus are popular corms. Tulips, hyacinths and daffodils are commonly fall planted, spring blooming bulbs.
Rhizomes and tubers are underground storage parts of some other plants, like iris and dahlias. Frequently, we call all bulbs, corms, rhizomes and tubers 'bulbs' in casual writing. The scientific name is 'Geophytes.'