|my crapes have a black ashy flim over them and didnt bloom well this year i've tried different chimals, could it be in my soil, the crapes in my back yard doesnt have this
|Answer from NGA
October 14, 2009
|What you describe sounds suspiciously like sooty mold which is a coating on the surface of the leaves. It happens when most often when aphids feed on the fluids within the tissues of the leaves above the affected leaves. When they feed they exude a sticky substance called honeydew. As this substance ages it turns into a black coating called sooty mold. So spraying your trees with different chemicals may not have actually killed the aphids, or did kill one generation but another arrived and began feeding all over again. You'll need to use a systemic insecticide or spray your tree with insecticidal soap (repeat sprays will be necessary). Neem oil based pesticides have some residual effect so you can try a neem oil to control the aphids (or mealybugs or scale insects) that are causing the sooty mold. Best wishes with your crape myrtles.
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