Dogwood anthracnose, caused by the fungus Discula destructiva, is a recent problem that kills flowering dogwood trees. Flowering dogwood trees are native in forests across Maryland and have been widely planted in yards and gardens. It is not known if the disease is a native or an introduced disease. It is not found elsewhere, but it behaves like other introduced diseases. Dogwoods have little resistance to it. This disease was first noticed in New York in the late 1970's. In 1983, it was found in Maryland on Catoctin Mountain and caused severe damage there. While it has spread across the entire State, there is more damage in the western part of the State where the climate is cooler and moister. Further, the fungus thrives in cooler moister weather occurring in early spring.
Early symptoms are spots that usually appear on leaves and flower bracts in mid to late May. Typical leaf spots are tan with dark purple borders and are variable in size and shape. Blighted gray and drooping leaves hang on the twigs. Symptoms appear during cool, wet weather and often diminish as the summer gets hotter and drier. The fungus spreads from the leaves to twigs and limbs. Diseased trees produce numerous epicormic shoots, or water sprouts, on the trunk and lower limbs. Cankers appear on the main trunk and eventually the tree dies. Seedlings also can be killed by the fungus. Long term effects of the loss of dogwoods are not known. However, wildlife habitats, visual qualities, and tree species diversity can be affected.