4 Types of Flower Bulbs That Gardeners Should Grow

A bulb isn't always just a bulb. Learn about the plants that grow from the types of flower bulbs, including tubers, rhizomes, corms 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 flower bulbs sold under the general term “bulb,” and they’re all a little bit different. Here’s what gardeners need to know.

Bulb

Ibulb Medres226350Courtesy Breck's Bulb Co.
Tulip bulbs are true bulbs

A bulb is the swollen fleshy stem of a plant, used to store food during dormant months. True bulbs (in other words,they are not rhizomes, corms or tubers) contain a plant’s budstem and leaves inside a compact unit with layers that  resemble the inside of an onion.Tulips, daffodils and hyacinth are bulbs, as are alliums.

Check out 5 deer-resistant spring bulbs.

Rhizome

Iris,rhizomes,for,plant,transplantation,,gardening,and,landscapingKhorzhevska / Shutterstock
Iris rhizomes

Rhizomes grow laterally underground, putting out new shoots along the way. Some invasive plants and weeds spread out via rhizomes to quickly dominate a landscape. Examples of plants that grow from rhizomes include canna lily, mint and iris.

Get expert tips for growing grape hyacinth flowers.

Corm

Gladiolus corms, types of flower bulbsSvf74 / Getty Images
Gladiolus corms

Corms are similar to bulbs and function in the same way. They resemble true bulbs, but are a solid unit of tissueunlike a bulb’s layers of developing leaves.New corms often grow on top of spent ones.They are often smaller and more bumpy in appearance, almost like rocks.

Gladiolus, crocus and freesia are all grown from corms.

Learn how to overwinter non-hardy bulbs.

Tuber

begonia tubers, types of flower bulbskoromelena/Getty Images
Begonia tubers

A tuber is basically a thickened rhizome. Tubers are underground stems and can bud from multiple spots. They can be divided to grow more.In some cases, like potatoes, we use them as food. Flowering tubers include begonias, dahlias and peonies.

types of flower bulbs Group Of Anemones Bulbs Vertical Close Up Selective Focus Background To Ad Copy SpaceDeborah Lee Rossiter / Alamy Stock Photo
Anemone tubers

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

Jill Staake
Jill Staake's lifelong love of nature turned into a career during the years she spent working with native Florida butterflies, caterpillars, and other wildlife at the Museum of Science & Industry in Tampa, Florida. During this time, she helped to maintain 30+ acres of gardens and backwoods, all carefully cultivated to support the more than 20 species of butterflies displayed indoors and out. She now writes for a variety of publications and sites on topics like gardening and birding, among others.