It is less common on other dogwoods and is not known to attack other tree species. The disease generally appears from late May to early July, but can be active during moist weather anytime in the growing season. Blotches usually have well-defined, dark grayish green, purple, or brown margins. Infected leaves usually drop early. Defoliation may be severe.
Dogwood leaves showing blotches and spots of the fungus disease dogwood anthracnose.
These are fungus fruiting bodies containing spores which spread the disease. Dogwood leaf showing a blotch which has spread down the mid-vein. The tiny dots in the blotch contain the microscopic fungus spores. Twigs are also infected. Sunken tan to brown spots with purple borders develop which eventually cause twig dieback.