I have azalea plants in which the leaves have become brown and black and sort of bubbled up and curled. I believe they are putting out a black mold that is turning our brick work and wood work (fence) black, and rotting the wood as well. The black is also on the concrete patio ground. Are you familiar with any of this? If so, any suggestions?
Certified GKH Gardening Expert
It sounds like the tree has sooty mold, which is actually an indicator of a pest infestation. Many times the pests that cause sooty mold are too small to see, but they can be damaging. I would recommend treating the plants with neem oil. This will treat both the pests and the sooty mold. Here is more information that may help: