Bleeding Canker

Bleeding canker is caused by Phytophthora species that invade bark and outer sapwood from infected soil. You'll see dark sap continuously oozing from large cankers on maples and other susceptible deciduous trees. The disease is particularly problematic in wet environments and irrigated landscapes where tree trunks are regularly wetted. Watch for sunken lesions with reddish-brown staining. Keep sprinkler irrigation off tree trunks and improve drainage.

Do not let sprinkler irrigation wet landscape tree trunks. Avoid ponding of water around trees. Prune affected branches well below visible symptoms and sterilize tools between cuts. Avoid pruning during wet weather, which spreads the pathogen through fresh wounds. Maintain plant vigor through proper watering and site management.