4 Types of Flower Bulbs That Gardeners Should Grow

A bulb isn't always just a bulb. Learn about the flowering plants that grow from tubers, rhizomes and more.

wren on iris flowerCourtesy Deborah Bryk
A house wren perches on a purple bearded iris bloom. Irises grow from rhizomes.

You’ll find several types of plants sold under the general term flower bulb, and they’re all a little bit different. Here’s what gardeners need to know.

Bulb

A bulb is the swollen fleshy stem of a plant, used to store food during dormant months. Tulips, daffodils and hyacinth are bulbs, as are alliums and onions. Check out 5 deer-resistant spring bulbs.

Rhizome

Rhizomes grow laterally underground, putting out new shoots along the way. Examples of plants that grow from rhizomes include canna lily and iris. Discover the top 10 lilies we love.

gladioli corms_lolik_/Getty Images
Gladiolus corms

Corm

Corms are similar to bulbs and function in the same way. They are often smaller and more bumpy in appearance, almost like rocks. Gladiolus and freesia are both grown from corms. Learn how to overwinter non-hardy bulbs.

begonia tuberskoromelena/Getty Images
Begonia tubers

Tuber

A tuber is basically a thickened rhizome. In some cases, like potatoes, we use them as food. Flowering tubers include begonias, dahlias and peonies.

Ready to add some new bulbs to your garden? We’ve rounded up the best websites for buying flower bulbs. Plus, check out the ultimate bulb planting guide to learn everything you need to know about growing these blooming plants.