WSU Extension


Honey locust : Honeylocust canker
(revision date: 6/23/2015)

Several fungi are responsible for cankers on honey locust in the Pacific Northwest. One problem, coral spot or Nectria canker, can result in sudden wilting or failure of infected twigs or branches to produce leaves. The slightly sunken cankered area may be indistinct until the fungus sporulates, producing pinkish-orange fruiting bodies that erupt through the bark. Branches may be girdled by the cankers, which are often associated with wounds. Nectria cankers also occur on black locust and many other plants. Both Fusarium sp. and Phomopsis sp. have also been associated with honey locust canker problems in Pacific Northwest nurseries.
Management Options

Non-Chemical Management
  • Prune out and destroy infected branches.
  • Provide proper culture. Proper fertilization and irrigation maintains vigorous, healthy plants that are more resistant to infection. Drought and heat stress are linked with Thryonectria canker development.
  • Avoid wounding trees.
  • Do not leave stubs when pruning.
Select non-chemical management options as your first choice!

Chemical Management

None recommended

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Caption: Honey locust Nectria canker
Photo by: R.S. Byther
Caption: Honey locust Nectria canker
Photo by: R.S. Byther