QUESTION: My azaleas have a strange problem. The leaves look yellow in places, but I can still see green. I don't see any insects.ANSWER: Yellowing of azalea leaves between the green veins is a clear signal of iron deficiency. This is a common problem that is easy to clear up. It is not caused by insect or disease, but just a mineral deficiency. The cause is usually a high pH. Waterlogged soil is another cause, but in that case, the plant usually dies of root rot first. Spray the azalea leaves with iron chelate.It may take a couple of sprayings to see good results. However, you should not depend on this alone to correct the problem long-term. It can be diagnosed by spraying the leaves with iron chelate.If the chlorosis is caused by iron deficiency, the foliage will become green within a week or two. This is not a permanent solution. That can only be done by lowering the soil pH.It is possible that lime used on your lawn got onto the azalea root zone. Take care that that doesn't happen.Use fertilizer that is formulated for acid-loving plants such as azaleas. Use pine needle or oak leaf mulch.

Nancy Brachey writes for The Charlotte Observer, 600 S. Tryon St., P.O. Box 30308, Charlotte, NC 28230.