Solving the mystery of bulbs

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By Master Gardener, Brunswick County Extension

A bulb garden is an easy garden to start because it only has to be planted once. However, when starting a new bulb patch, sometimes flowers that were planted by previous gardeners are unearthed. Use this guide to identify the most common garden bulbs and what they will turn into when in flower.

Look at the shape of the bulbs that you have and separate them according to size, shape and hardness. Set aside one pile of bulbs that have a Hershey’s Kiss shape and a soft, pliable surface. Put all the smaller, firmer bulbs into another pile together. Put all of the bulbs that spread out like roots together in third pile.

Pick up bulbs from the first pile that are shaped like Hershey’s Kisses, and feel them with your fingers. They should be a little soft to the touch, and can come in many different shapes. These are true bulbs. True bulbs are so named because they hold all of the nutrients they need inside the bulb. Some common true bulbs are lilies, tulips, irises and daffodils. If the bulb has a brown wrapping like an onion and is 1-1/2 to 4 inches long, then it is a tulip. Bulbs that are tan colored and 2-5 inches across with a lumpy shape are daffodils.

Feel the bulbs from the second pile. Those that are very hard to the touch and on the small side are corm bulbs. Some common corm flowers are crocus, water chestnuts and gladiolus. Pull out any that are small, hard, round and reddish brown. They should be 1-1/2 inches long and look like an onion. These are crocus bulbs. Plants grown from corms are often grouped in with bulbs, but corms do not have the fleshy leaves you would find on a bulb and the bud is on top of the corm. 

Bulbs that are tear-shaped and tan in color with a 1 to 3-inch stem on the top are irises. If there are any with tentacle-like roots sticking out, then they are probably root bulbs. Pull out any that are dark brown with a lumpy bottom and stalks sticking out from the top. These are Canna lilies. Lilies, hostas, iris, Solomon seal, ginger, trillium and day lilies are all grown from rhizomes and may also be referred to as creeping rootstalks or rootstocks. If rhizomes are broken into pieces, each piece may be able to give rise to a new plant. This is a process known as vegetative reproduction and is used by farmers and gardeners to propagate certain plants. Examples of plants that are propagated this way include hops, asparagus, ginger, irises, Lily of the Valley, Cannas and sympodial orchids. Many invasive plants spread by rhizomes, for example ground ivy. There are also many cultivated plants that travel by rhizomes, such as Lily of the Valley.

Tubers are basically swollen, underground plant parts that store food. There are two types of tubers. A root tuber is an enlarged root that stores food for the plant and from which shoots will grow. A stem tuber is the enlarged tip of a food storing rhizome or underground stem. Tubers are sometimes grouped in with flowering bulbs. Dahlias are a good example of root tubers. Examples of stem tubers are tuberous begonia and cyclamen. 

Once you know what kind of bulbs you have, decide the best placement for them. Bulbs are usually planted in the fall before the ground freezes so they can bloom as the earth warms. It helps to mark which bulbs go where so you know what is going to sprout where in the spring. Keep in mind that some bulbs bloom earlier than others. So, if you want a continuously blooming bulb garden, plant varieties that will come on at different times. Keep in mind that in southeastern North Carolina spring blooming bulbs should be planted in November or even December if the weather remains mild. Tulips are beautiful but must be treated as an annual in our weather zone, as they need an extended cool period to bloom again the next year. 

Send your gardening questions or comments to: Brunswick County Master Gardener Column, P.O. Box 109, Bolivia, NC 28422, or call 253-2610. Enclose a self-addressed, stamped, envelope if requesting information or a reply. Answers may be printed in this column. Visit the Extension Service website at www.ces.ncsu.edu/brunswick/ or access the site through the Brunswick County Government online website at www.brunsco.net.