My crape myrtles have a black sooty coating on them. What will get rid of it? I have been spraying with something I got at the garden center. It lists a lot of things it is supposed to help with and names a fungus as one of the things , but I'm not sure if this black stuff is a fungus. I have only sprayed three times so maybe it takes a while for it to work. Should I give it more time?
