Bulb Definitions

Gardeners tend to refer to any plant with an underground storage organ as a bulb, but there are actually many different categories.

bulb
Many true bulbs are
surrounded by an outer tunic.

True bulbs are made up of modified leaves that are attached to a flat basal plate and that surround the following season's bud. Many true bulbs, such as tulips and narcissi, are surrounded by a papery outer tunic. In others, such as lilies and fritillarias, the bulb is covered by fleshy scales.

corm
Corms have a solid starchy interior stem.

Corms look like bulbs on the outside, including the flat basal plate and the papery tunic. But when they are cut open, they have a solid starchy interior stem. Crocuses are an example of typical corms.

In the final section, we'll define tubers and rhizomes.

Want more information about bulb gardens? Try these:
  • Planting Bulbs: Learn how to plant bulbs in your garden.
  • Bulb Garden Care: Find out the ins and outs of caring for a bulb garden.
  • Tips for Growing Bulbs: Check out tips for growing these unique plants.
  • Bulbs: Discover all you need to know about bulbs in this article.
  • Bulb Gardens: Learn how bulbs can create a lovely garden.
  • Gardening: We answer all of your general gardening questions in this section.