Althea

I live in TN about 40 miles from Nashville. I have a lot of Althea bushes and today I found on my double pink there is something wrong with the leaves, looks kinda molded with some black on them. Please help. Thanks, Cynthia

Anne's response:

I think the plant you are referring to is Hibiscus syriacus or rose-of-sharon. Aphids and whiteflies may cause the damage you describe as can the fungal disease powdery mildew. At this time of year the better control is to keep diseased leaves raked up from beneath the plant and as daytime temperatures are in the sixties spray the plant with dormant or horticultural oil. Oil sprays smother over-wintering insects and disease spores.