Bacterial Canker in Cherry Trees: Sap Oozing and Rapid Leaf Death

Northern Virginia cherry tree lost ⅔ leaves in 2 weeks with multiple trunk sites oozing sap during extreme heat/humidity despite regular watering.

Diagnosis

Sap oozing from trunk wounds indicates boring insect invasion or bacterial canker (Pseudomonas syringae). Bacterial canker causes leaf discoloration, premature drop, amber gum oozing from bark lesions, and limb dieback. It thrives in cool, moist conditions.

Management

Wipe sap to check for 1-3mm entry holes. Prune cankered branches with alcohol-sterilized tools between cuts. Apply copper fungicide in fall. Destroy all debris. No effective growing-season chemical control exists.