Anthracnose is a foliar disease

Anthracnose is a foliar disease and affects a large population of shade trees. This disease often appears serious but in reality it rarely kills a tree.

What trees and shrubs are affected?

  • Ash
  • Sycamore
  • Dogwood
  • Oak
  • Maple
  • And More

✓ Symptoms

Anthracnose is caused by a variety of different fungi. The spores released from the fungi infect newly emerging leaves. Tan, brown or black spots begin to develop on leaves near the leaf veins. The discoloration spreads outward from the vein and the tree may be partially defoliated. Cankers may be present on the stems and branches. In most cases, after a tree has been affected by anthracnose, it will defoliate in spring and regenerate new growth by summer.

✓ Solution

Most trees are able to withstand anthracnose though it can weaken a tree considerably over several years. When anthracnose is suspected, collect and discard all fallen leaves and branches. Prune off any branches with cankers that contain fungal spores. This sanitation will minimize the possibility of re-infection the following year. The disease will stress the tree, so light fertilization, water and mulch are all recommended to boost tree vigor. Fungicides sprays can be unreliable and fairly expensive. When spraying newly emerged foliage on large trees, it can be difficult to get complete and effective coverage.