Anthracnose is a catch all phrase to describe leaf and shoot disease on many types of trees and shrubs. In green ash trees anthracnose appears, usually in the spring, as sudden leaf loss. A wet spring, along with the presence of the fungus, contributes to anthracnose severity. Fallen leaves are usually smaller, they may have a brownish red spot(s), blackish burnt edges or no sign of leaf blight at all. Treating with a fungicide prior to symptom development is the only effective form of treatment. Our recommendation is to not treat for this usually harmless disease in green ash.