It is a serious disease capable of killing large numbers of trees and most Cornus species can become infected. The first symptoms that appear in the spring are spots on the leaves and flower bracts. Leaf symptoms develop first in the lower canopy and progress up the tree. Infected leaves have tan spots with purple edges, dry brown margins or large blotches on them. Blighted gray or drooping leaves hang on the twigs and are often the first symptoms noticed during cool, wet weather.
Cankers can girdle and kill individual branches or twigs.
Multiple cankers can girdle the main trunk and eventually kill the tree. A combination of cultural and chemical measures is necessary to control this disease. Effective control may be possible if the disease is detected before branch dieback begins. During hot, dry summer weather, prune and remove all dead twigs and limbs. Rake and remove fallen leaves.