Key points
- The fungus Elsinoë corni causes spot anthracnose primarily on Cornus florida. This disease should not be mistaken for another more serious dogwood disease called dogwood anthracnose caused by the fungus Discula destructiva.
- The disease can infect flower bracts, leaves, and fruit. The fungal lesions are about 1/8 of an inch across with a tan center surrounded by a reddish-purple border.
- These spots can be numerous and often fall out producing a ragged leaf appearance.
- The fungus overwinters on twigs and infections begin as new growth emerges in the spring.
- This disease is worse in wet weather.
Management
- Plant cultivars resistant to spot anthracnose.
- Rake and discard symptomatic foliage.
- Since disease severity is sporadic depending on how wet the spring season is routine fungicide applications are not recommended.
- Fungicides will not cure visible symptoms. If spot anthracnose is severe on young trees, they can be protected with a registered fungicide applied in the spring at bud break followed by additional sprays every 7 - 14 days until leaves are fully expanded.
