Posted: May 6, 2017 at 1:52 a.m.

Arkansas Democrat-Gazette How to grow Illustration

Q My 3-year-old gardenia bush has turned black. Most of the leaves are black with a velvety feel. The black can be scraped off, and the leaf looks normal underneath. Is this winter damage or blight? Is there anything I should do about it?

Fringe tree, Chionanthus virginicus, can be grown as a shrub or a small tree.

The native mayapple is a spring ephemeral.

A The black substance is called sooty mold and is a byproduct of a sucking insect. Aphids, whitefly and scale can all give off a sweet substance called honeydew as they feed on your plants. Wherever the honeydew falls -- leaves, patio furniture or cars -- a black sooty mold will eventually grow. Gardenias are usually pretty susceptible to whiteflies. These insects are pure white as adults and flutter around the plants when disturbed. They lay oval egg sacs on the undersurface of the leaves and overwinter there. Most likely, the damage you are seeing is a result of last year's insect feeding. You can hose off the plant to try to remove the black, but new growth should be clean. Monitor for insects this season and try to prevent their spread.

Q Something is wrong with my azaleas. There are several odd growths on them. The leaves are really thick and turning white. Am I going to lose my plants?

A The late cool, wet weather we had was enough to cause azalea leaf gall. While the galls look awful, they are not that harmful. As soon as you see the thick, fleshy leaves, snap them off or prune them out and throw them away. You want to remove them before they begin to turn white. They usually start a bright apple green and turn gray and then white as they produce spores for next year. Now that the weather has warmed, they will stop causing any more damage.

Q I live in Heber Springs on the Little Red River. This small tree/bush is in my neighbor's yard and we don't know what it is. Can you identify it for us?

A The plant is Chionanthus virginicus, commonly called old man's beard, grancy graybeard or fringe tree. It can be grown as a small tree or a large bush and is quite showy in the spring.

Q We own a farm at the southernmost part of the state in Union County. This plant appears every spring in the wooded areas on our property. I've never heard anyone say what they are and would love to know more about this plant. Any ideas?

A It is a wonderful native plant called mayapple -- Podophyllum peltatum. These large leaves show up every spring, and a showy white flower hangs beneath them. The fruit is small, round and edible, and turns yellow when ripe. The rest of the plant is poisonous. They are typically a spring ephemeral, meaning they appear every spring, flower, set fruit and then disappear for the remainder of the season. They colonize over time, spreading out and giving you quite a pretty show in the spring to early summer.

Q I moved some houseplants outside a few weeks ago, and one of the palms has brown leaves everywhere. Did I move it outside too early and do you think it is dead?

A Mid-April should be fairly safe for moving houseplants and tropical plants outside, although it did get a bit nippy one night or two. My guess is that the plant was sunburned. Inside our houses (even when they get bright light) plants are protected from the direct rays of the sun. Exposure to direct sunlight can result in sunburn. Unlike humans, plants turn white or brown instead of red. In the future, gradually expose your plants to sunlight. For now, cut off the damaged leaves, water and fertilize, and new growth should appear.

Janet B. Carson is a horticulture specialist for the University of Arkansas Cooperative Extension Service. Write to her at 2301 S. University Ave., Little Rock, Ark. 72204 or email her at

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