Dogwood borer is a frequent pest that can result in added tree injury and stress. Check the main trunk and branches for signs of dogwood borer in early spring and in early fall, infested trees develop seeping cracks containing piles of sawdust-like frass. Mechanical damage to tree trunks, such as that caused by lawnmower injury attracts borers. For further information on dogwood borer see publication E-41 . Recommendations for Managing Insects and Mites on Shade Trees and Shrubs , available from your local county extension office.
Good sanitation is especially important for trees infected with anthracnose.
Prune out and destroy dead and dying twigs and branches and rake up fallen leaves to help reduce potential sources of inoculum and improve tree appearance. It is also advisable to prune out water sprouts which develop on the trunk or main scaffolding limbs since they are very susceptible to infection from anthracnose. Prune only under dry conditions and sterilize pruners with alcohol between pruning cuts. Avoid planting monocultures of flowering dogwood, Cornus florida . There are no flowering dogwood cultivars known to be resistant to dogwood anthracnose.