No chemical control is available. Prune out diseased branches and prevent the disease by keeping trees healthy. Leaf spots caused by various fungi can be a problem. These are not serious so no chemical controls are listed. Clean up and dispose of diseased leaves.
Powdery mildew causes a white powdery growth on the leaves.
Sprays of benomyl used according to label directions should take care of the problem. Fall Care Kits Prepare your trees and shrubs for winter with this kit containing specially formulated fall fertilizer and the TreeHelp Bug Band insect trap.