Questioni have a crepe myrtle in my front yard and two gardenia bushes in my back yard. all three have what looks like soot on their leaves. all three appear to be growing and new grow looks normal. what is causing the leaves to look black and what can i do?
AnswerI would suspect you have aphids on the leaves. These are small isects that suck the juice out of the plant leaves. The extrement they produce is called honeydew and is sticky. A funus (black sooty mold) will grow on the honeydew turning the leaves black. Control the aphids and the black goes away. Check with a local garden type store for a systemic insecticide for aphids and spray the leaves. This will control your problem.
