Ornamental Cherry: Bacterial canker

categories: Ornamental Cherry Ornamental Cherry Diseases Ornamental trees Ornamentals

revision date: 2022-11-26 01:57

Bacterial canker on tree trunk.
Bacterial canker on tree trunk
Photo by: R.S. Byther


Bacterial canker can be found on any part of the tree. The disease causes cankers and dieback of twigs and branches. A typical branch canker is elongate and enlarges during the dormant season from around the base of an infected twig. It may leak sap (gumming) at the edges of the canker and may show brown or black streaking in the wood when cuts are made at the top or bottom of the canker. Cankers can girdle limbs or trunks. Bacterial canker can kill buds in winter and blossoms in the spring, and can also cause dead spots on leaves. In combination with frost the disease can cause serious damage to trees.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

  • Locate trees in areas least likely to be affected by frost.
  • Prune and destroy infected branches before wet weather begins in the fall. Make pruning cuts well below infected area and disinfect tools between cuts.
  • Do normal pruning in January or February.
  • Remove severely infected trees.
  • Cauterizing (burning out) cankers with a propane torch has had some success.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

  • Apply fixed copper before fall rains, during leaf fall and late dormant just before buds open.
  • Homeowners should not make foliar applications to trees over 10 ft tall.
  • Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.

Approved Pesticides

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.

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