Maple: Anthracnose
categories: Maple Maple Diseases Ornamental trees Ornamentals
revision date: 2022-11-25 10:14
Photo by: R.S. Byther
Biology
Maple anthracnose is a fungal disease affecting leaves and sometimes twigs. Infected leaves develop discrete brown spots and/or blotches, often at leaf tips and often associated with the main or secondary veins. Japanese maples tend to develop reddish-brown to light tan blotches. Small brown fruiting bodies may be seen in the affected areas. Diseased leaves of all maples may drop prematurely, sometimes resulting in severe defoliation. The disease occasionally causes twig cankers, where the fungus can overwinter. Cankers may also girdle twigs, causing tip dieback. The disease is favored by warm, wet springs.
Management Options
Use Integrated Pest Management (IPM) for successful plant problem management.
Non-chemical Management
Select non-chemical management options as your first choice!
- Rake and destroy all fallen leaves.
- Prune out and destroy infected twigs during the dormant season.
Chemical Management
IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.
- If needed, apply in spring during budbreak and early new growth.
- Homeowners should not make foliar applications to trees over 10 ft tall.
- Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.
Approved Pesticides
Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.