We’re sure you’ve heard all these terms before, but the differences between them can be a bit confusing. So let’s talk about which is which, and what the differences are.
Bulbs
A bulb is formed from the plant stem and leaves. The bottom of it is made up of a small disk called the basal plate, which is basically a compressed stem. And these roots grow from the bottom of the basal plate. Then you have layers of leaves that kind of resemble scales, which are filled with food and nutrients. This all sits on the basal plate and surrounds a single bud that will eventually become next year’s flower. Examples include daffodils, lilies and tulips.
Daffodil, Lily and Tulip Bulbs
Corms
Similar to a bulb, in that it also comes from the stem of the plant, but corms are actually a solid tissue that doesn’t have any separate scalelike leaves. Instead, a dry, papery outer layer protects the inside. After the stem sprouts from the top of the corm, little buds pop up from the stem and turn into flowers. Examples include crocus and gladiolus.
Gladiolus Corms
Tubers
Lastly, there are tubers, the best-known example of which is a potato. A tuber is a storage organ formed from a stem or root. This organ develops eyes (or buds) all over its surface. Shoots grow upward from the buds and form plants. Other examples include cyclamen, dahlias and tuberous begonias.
Dahlia Tuber
Rhizomes
A rhizome is a swollen length of underground stem that grows horizontally and forms roots on its underside while leaves and new stems sprout from the top. And buds form at intervals along the structure of each stem. Some of the most persistent plants come from rhizomes, such as bearded iris, cannas and trillium.
Bearded Iris Rhizome
Taproots
These are deep, central roots that grow straight down from a plant, helping to anchor the plant firmly and access deep water and nutrients. When planting, it’s essential to ensure the hole is deep enough to accommodate the entire taproot without bending or crowding it. Properly planted taproots allow these plants to thrive in your garden. Some examples of taproots include hibiscus, lupines and hollyhocks.
Hibiscus Taproots
Fibrous Roots
This type of bareroot is a dense network of thin, branching roots that spreads out from the base of the plant. Unlike taproots, they don’t have a central main root but consist of many roots of a similar size. This type of root system helps stabilize the soil and efficiently absorb water and nutrients from the surface layers. Examples include coreopsis, echinacea, rudbeckia and many ferns.
Echinacea Fibrous Roots
Tuberous Roots
They are thick, swollen roots that store nutrients and water, aiding plant survival and growth. Found in plants like daylilies and hostas, these roots are crucial for energy storage, especially during dormant periods. When planting, ensure the tuberous roots are spread out in the hole with the crown slightly above soil level. This aids in vigorous growth and producing beautiful blooms.
Hosta Tuberous Roots
Roots with “Eyes”
This type of bareroot refers to tubers or rhizomes that have growth points or “eyes.” These eyes are small, budlike structures from which new shoots and roots emerge, and are crucial for propagation. When planting, it’s important to position the roots so the eyes are just below the soil surface. This ensures the new shoots can easily break through the ground, leading to healthy growth. Peonies, astilbes and dicentra are examples of these bareroots.
Peony Root with “Eyes”
There you have it! We’ve characterized the major differences between bulbs, corms, rhizomes, long taproots, fibrous roots, fleshy tuberous roots, roots with “eyes” and tubers. As the saying goes, “The roots of wisdom grow in the soil of experience!”