Project Description

 

Dogwood Anthracnose

A leaf and twig disease that is extremely harmful to flowering dogwoods. Usually, Kousa dogwoods are resistant to infection. Shortly after the leaves have expanded (mid-late May and June), spots and blotches of varying shape and size appear on infected trees. In some cases, entire leaves may become infected and die. Many drooping, brown, dried leaves remain on the stem throughout the fall and winter. When the whole leaf is affected, the infection may then proceed through the petiole of the leaf into the stem causing stem cankers. Infection of the stems and shoots may also occur directly. Over time, infection of twigs and shoots by these cankers kills branches, usually beginning with those low on the tree and moving upward. The tree may attempt to compensate by sending out sprouts from the trunk, but the fungus easily infects them. Infection of the sprouts usually spreads quickly to the trunk and causes severe cankers with split or buckled bark. Affected trees may die within 1-3 years; saplings may die in the same year they are infected. Sanitation pruning and removal of diseased leaves is a must. Replacement with resistant varieties suggested. Spray treatments are also recommended.