What is the difference between bulbs, corms, tubers and rhizomes?

Published April 10, 2012 | By Jane

Bulb onions are true bulbs you can grow in the home garden and enjoy in the kitchen.

Beginners and experienced gardeners can often use the terms bulbs, corms, tubers and rhizomes interchangeably. But there is a difference. All these are adaptations in which plants store food and allow the plants to die back into dormancy staying safe over periods when growth is not hospitable. In short these are swollen packages in which a plant life is stored. Yet there is a difference in each of the storage forms between bulbs, corms, tubers and rhizomes.

Bulbs are interesting because essentially they are miniature baby plants enclosed in a layered format. Picture an undeveloped bud with the beginnings of a stem and surrounded by layers of leaves all condensed into a small package – sometimes even encased in a papery wrapping. Familiar bulbs would be tulips, daffodils, hyacinths and the familiar onion.

Corms may look a lot like bulbs but they function differently. These are adapted root systems that contain food for the plants but do not encase immature leaves or flowers. Think of them as solid little containers filled with the nourishment the plant will need until roots can form and take over as the contents of the corm is used up. Always leave leaves to die back naturally after the plant blooms so the energy can drain back down to the roots to form new corms for the next year’s growth. Examples of corms are lilies, Crocosmias and gladiolus.

Tubers are usually rather lumpy-looking, living containers that are a compact, compressed food source studded with ‘eyes’, or growth points from which plant leaves and stems will grow. The potato is a typical tuber, but so are Dahlias, Anemones and Ranunculus.

Rhizomes are actually adapted swollen stems, often bumpy and somewhat flattened. All bud and grow from the storage stem that lays on or under the ground like a bulb or tuber. You might recognize the rhizome in the form of a fresh ginger root, the Bearded Iris, or the Canna Lily.

Originally posted 2011-02-13 06:32:49. Republished by Blog Post Promoter

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