Anthracnose FAQ

Get all the key information about anthracnose in Ontario, a common disease affecting trees and plants. Contact us for more information.

Q: What is Anthracnose?
A: A disease present on the bud of the twig that spreads during damp cool spring weather.

Q: How does Anthracnose affect the tree?
A: In the spring, as the tree begins to produce leaves, the disease is carried from the buds onto the leaves causing the leaves to turn brown and fall off.

Q: Which trees are affected by Anthracnose?
A: Native and imported species of Ash, Maple and Oak.

Q: What will happen to an infested tree?
A: The disease is non-fatal to healthy trees. Your tree will have little or no leaves until late June or early July so you may think your tree is dead, but the tree may start producing leaves after this time.

Q: What signs should I look for in my trees?
A: When leaves are full grown, dry brown and black blotches form on the edge of the leaves and then spread to the whole leaf. The leaves will drop to the ground in late May and early June.

Q: What is the prevention or treatment?
A: Raking up the leaves in the fall and putting them out for yard waste helps reduce the return of the disease the following spring. Fertilizing and watering can help the tree put out new leaves. We can provide some suggestions based on your trees assessment.

Q: Where can Anthracnose be found?
A: It can be found all across Ontario.

If you believe your trees could be infected with Anthracnose or if you have any inquiries, please contact us!


The above is general information and does not try to address or endorse any particular product or activity related to the pests as they affect trees.