Fact Sheet

Nectria Canker

Have you noticed red spots on tree bark, especially after rain or in damp weather?

It may be from a condition known as nectria canker. It can cause damaged areas on your tree that will seem to be getting worse instead of healing, especially around old pruning wound or bark injuries.

The Problem

During rain or moist weather, spores are produced on infected areas. These spores are dispersed by wind or water and enter a new site through bark in areas damaged by sunscald, hail, frost cracks, and pruning wounds, particularly from improper pruning.

Symptoms and signs include:

Small white, orange, or red fungal spots

Co-occurring issues or look-alike symptoms:
Host dependent.

The Vineland Prescription

For nectria canker treatment, pruning out infected branches can work for small infections.
Do not prune honeylocust in wet conditions.
Avoid pruning other susceptible trees in wet weather if active cankers are observed.

The Prognosis

Trees can generally survive for long periods with cankers. If a canker encircles a branch or trunk, the entire branch or tree will be killed.

Contact Our Experts

From questions to estimate requests, contact us about your residential or commercial project.