What Is Anthracnose?
Anthracnose is a common leaf disease caused by several different kinds of fungi. These various fungi typically infect newly emerging leaves in spring. Infected leaves will develop tan, brown or black blotched areas. Leaf distortion is also a common effect. Anthracnose can also affect stems and branches in some trees and shrubs. Symptoms tend to be worse when spring weather is cool and wet. Anthracnose can be unsightly; however, it will not result in the death of your tree.
Trees prone to Anthracnose include: Oak, Maple, Ash, Hickory, Sycamore, Walnut, and other shrubs and garden plants
How to Identify Damage Caused by Anthracnose
Early Signs
Change in Color
In spring and early summer leaves will develop brown or black areas on the leaves.
Spores
Spores spread during cool and rainy weather.
Cankers
Infectious cankers on twigs and branches.
Abnormal Leaves
Leaf distortion such as spots, curling, and crispy edges is also common.
Late Signs
Leaf Changes
Foliage will appear damaged and some leaf drop may occur.
Dead Tree
Depending on the serverity, your tree may die. Signs include no leaves or needles, brittle branches, peeling bark or fungi growth.
Re-leaf
Most trees re-leaf by mid-summer.
Anthracnose Prevention
For Homeowners
- Raking up and disposing of infected foliage may help lessen the disease in proceeding years, composting of leaves is the best method of disposal.
- Supplemental watering of trees if summer is dry would be beneficial.
For Professionals
- Provide proper diagnosis.
- Provide guidance for overall tree care.
- Suggest management strategies to combat the disease.
- Use of foliar or systemic fungicides to combat the disease.
Anthracnose Treatment
Step 1
Spraying of trees preventatively with the proper fungicide may be prescribed.
Step 2
Proper pruning of infected or dead stems and branches is advised.
Step 3
Fertilization and/or other soil treatments to imrpove tree vigor.
Anthracnose FAQ
Frequently asked questions about Anthracnose.
Can trees be sprayed in summer when the disease is evident?
No. Often the trees need to be preventatively treated in the spring as the leaves are developing for best results.
Will my tree get anthracnose every year?
Some trees are more susceptible than others, however, weather conditions are the primary factor in severity from year to year.