Q: The bark is peeling on my white crape myrtles, is this normal?

LORRAINE LANE, e-mail

A: The peeling bark, called "exfoliation," is normal and attractive on "Natchez" crape myrtle. Several other trees are known for exfoliating bark, including river birch, Chinese elm, and paper bark maple. The peeling bark reveals a contrasting color of inner bark, which leads to great winter interest.

Q: Are there any systemic fungicides that could be used like a systemic insecticide by pouring around the base of a plant?

NEAL SHIREY, e-mail

A: There are indeed systemic fungicides, but their use is not as simple as with systemic insecticides. Since the chemicals in products often change, you'll need to read the active ingredient label to find the chemicals I mention. Myclobutanil, tebuconazole, propiconazole, thiophthanate-methyl and triadimefon are systemic fungicides available to homeowners in various products. Some are designed to be sprayed on foliage, and some are drenches. Chlorothalonil and copper ammonium complex are contact fungicides. The shortcoming of systemic fungicides is that fungi build up resistance to them more readily than with contact fungicides. Practically speaking, it is cheaper and more environmentally sound to choose disease-resistant plants and manage them properly than it is to count on systemic fungicides to protect them.

Q: Recently I read an article about using peppermint spray for bugs on flowering plants. Have you ever heard of this?

DONNA DOTSON, e-mail

A: Indeed there are several plant oils being sold as insecticides. Clove oil, peppermint oil, lemon oil and corn oil are all ingredients in "organic" insecticides. Oils can be somewhat effective but, like any chemical, they can be harmful if you are exposed to too much. I once got

a blinding headache from citrus oil that spilled on my clothing so that I smelled the fumes for an hour. Read and follow label directions for these products. Do not attempt home-made concoctions using drugstore oils.

Q: My mother has crape myrtles on which flying bugs have taken over. She says they are slowly dying, and the leaves are oily looking. They also get on the hood of her car and turn it oily.

WAYNE MARTIN, South Alabama

A: Undoubtedly they are crape myrtle aphids but I'm going to try to persuade your mother not to control them with insecticides. According to Russell Mizell and Gary Knox at the University of Florida, crape myrtle aphids and their oily, sugar-filled honeydew serve as food for 20 species of beneficial insects. The abundance of food encourages good insects to remain in her garden. Lady beetles in particular feed on aphids. If your mother didn't have the crape myrtles, she might have worse insect problems in her garden. I hope you'll advise her only to occasionally wash the tree bark, as well as her car, with a water hose. Water dissolves sticky honeydew and prevents it from turning black. No other control is usually warranted.

Listen to Walter Reeves Saturday mornings on WSB-AM (750) from 6 to 10. Call 404-872-0750 or e-mail georgiagardener@yahoo.com to ask questions. Tune in to Walter on "Gardening in Georgia" at 7 p.m. Thursdays and 12:30 and 6:30 p.m. Saturdays through October on GPB.