Galls on the plant crown are not easily pruned off so destroy the whole plant. Avoid infested soil. Rose anthracnose causes purplish brown, circular, one-half inch leaf spots. The center of the spot turns gray and drops out. Black spot sprays generally control this disease.
Black spot causes black spots on the leaves.
The leaves turn yellow and drop. Remove and destroy fallen infected leaves. Botrytis blight causes flower buds to turn brown and decay. The petals of unopened flower buds are easily lifted off the stem. Remove old flowers as they fade.