Growing Begonias: Begonia Bulbs In The Garden

By Heather Rhoades

Image by Arthur Chapman

If you think you’ll be planting begonia bulbs this year, think again. For that matter, if you think you’ve ever planted begonia bulbs, well, you might want to sit down. That’s right folks – there is no such thing as begonia bulbs in the garden!

Growing Bulbous Begonia Plants

While some of you may believe you are growing begonia bulbs in the garden, you really are not. It may seem like a minor technicality, but what you may be thinking is a begonia bulb is actually a tuber or a rhizome, depending on the type of begonia. There are also fibrous rooted begonias but, alas, no begonia bulbs. At this point, you’re probably asking yourself, “Well, what’s the difference?”

In actuality, there’s a big difference when growing begonias.


When you cut open a true bulb you’ll find the flower and leaves all wrapped up in a nice tight package. A bulb contains five major components. There is the basal plate (the flat circle on the bottom where the roots grow), fleshy scales (primary storage tissue), the tunic (skin, like that on an onion), the shoot (the developing flower), and lateral bulbs (which develop into offsets). Common plants that come from bulbs are tulips, lilies and narcissus – but not begonia.


A tuber grows close to the ground’s surface and has many growing points. Unlike the bulb, tubers do not have basal plates and do not have a protective covering. Tubers aren’t as hardy as bulbs, so they have to be dug up in the fall. The most common tuber, of course, is the potato. Other plants that grow from tubers are anemones and tuberous begonias (surprise!).


A rhizome is a swollen stem that usually grows horizontally underground and sends up leaves and flowers at intervals. The are also referred to as “rootstocks.” Common plants that come from rhizomes are irises, cannas, and calla lilies. Occasionally, you may find a tuberous begonia listed as rhizomatous.

So now that you’ve learned a little something new about begonia bulbs in the garden, you’re probably ready to find out more about these plants (that’s why you came here in the first place, right?). For information about begonias, check out this article. Oh, and before you go, repeat after me, “There is no such thing as a begonia bulb!”