I have two gardenia bushes planted outside that produce a lot of blooms. Suddenly the leaves have turned black with a crispy black film that looks like it is peeling off on some of the leaves. What is the cause of this, and is there something I can do to correct it?
Gardenia Leaves Turned Black
Certified GKH Gardening Expert
It sounds like you have sooty mold. It is normally a sign of a pest infestations. I recommend treating the mold and pests with neem oil. Here is some information that can help you: