A Greener View by Jeff Rugg

Q: I bought several indoor hibiscus plants and they are thriving. However, they were outside all summer and are now too tall for my kitchen garden window. I don't have room for plants that large. I wonder if I cut them back, will they still live and bloom?

A: Pruning is actually quite easy. The main pruning should be done after they finish blooming. That will probably be in the fall. After a plant stops blooming, it is the proper time to cut just about everything, unless you want to eat the fruit produced from the flowers. Pruning prevents the plant from wasting energy on seeds and sends it back into production of more flowers.

Hibiscus, in particular, bloom on the ends of the new growth. The plant will go somewhat dormant over the winter if it gets less light, cooler temperatures and less water. In the spring, it will begin to grow again. You may find the need to clip off a branch or two, but don't keep pruning it back or else you will remove all the flower buds, since they develop on the ends of the branch.

The pruning you do now can remove as much as one-third or one-half a branch. All small interior branches can be removed, and any branches that angle inward though the middle of the plant should be cut off. Make the cuts just above a leaf or bud. The bud should be facing the outside of the plant, not aimed toward the middle. Branches that are completely removed should be cut to leave a small bump, not a long stub.

There should be a live bud where there is a green leaf. Farther down the branches where the leaves have already fallen off, the buds may or may not be alive. Don't just cut back a branch into the middle of nowhere; look for buds and cut back to them.

A lot of hibiscus are sold in the spring at the big-box stores. They make beautiful patio plants and can be grown in the house if given the right conditions.

They are tropical, and you will need to bring the hibiscus in for the winter. You shouldn't wait until the day before a freeze to do it. Indoors, the best temperature range is between 55 and 70 degrees, so bring it in while the outdoor temperatures are in that range.

Before you bring it in, do all the fall pruning to remove the majority of insects. Most insects live on the succulent growth near the end of the branch, so pruning removes them. Fall pruning also eliminates most of the leaves that would have fallen off indoors when they didn't receive enough light. After you trim the plant, wash it off with a little insecticidal soapy water to kill off even more insects. Too much soap will kill the leaves.

You can expect the hibiscus plant and most other plants brought indoors for the winter to be somewhat dormant until the spring sunlight and warmth starts to waken them. A big problem with these plants is they get overwatered — don't leave water sitting in the saucer. Misting the leaves to keep up the humidity is helpful. High humidity and occasional washing will keep spider mites and aphids off the leaves. Don't forget to wash behind the ears; I mean under the bottom of the leaves where many insects hide. You can run small plants under the sink and large ones in the shower. It is helpful to occasionally dust the leaves, too.

A west or south window will help give warmth and sunlight to the hibiscus. Keep it out of dry drafts from the furnace and cold drafts from open doors.

In the spring as new leaves appear, you can repot the plant into a pot that is an inch or 2 inches larger in width. Use a lightweight potting mix or add peat moss to a normal potting soil. Adding slow-release flowering plant food will help promote more flowers. Liquid fertilizers can be used every few weeks in the active growth periods of spring and summer.

E-mail questions to Jeff Rugg, University of Illinois Extension at jrugg@illinois.edu. To find out more about Jeff Rugg and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

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