Q.My gardenia leaves have a black coating; how and what to do to get rid of
My gardenia is the shape of a tree; it has black stuff on top of the leaves. I would like to know what this is and how to treat it. This plant is I know 5 years old and I don’t want to lose it so please help.
Certified GKH Gardening Expert
Your gardenia likely has sooty mold, which forms on the honeydew left by sucking insects. If you examine the undersides of your leaves you should find the culprit. Often it is whiteflies, aphids or scale. Here is an article that tells you how to get rid of the insects. Then the mold will go away or can be wiped off.