- Purple ringed leaf spots
- Spots on buds, bracts, & stems
- Appears when dogwoods bloom
Dogwood spot anthracnose symptoms appear in early spring, just before or during bloom. Light brown to dark purple spots form on the upper surface of host leaves, on the pink, white, and yellow bracts, and on young, growing stems. These spots develop grey to tan centers as the leaf dies and the fungus begins producing spores. Affected leaves and bracts become misshapen as the season progresses. Stem spots are small and rarely seen This disease rarely causes entire leaves turn brown, defoliation, or branch dieback. If this is observed later in the season, it is likely due to Septoria leaf spots. Dogwood spot anthracnose (Elsinoe corni) lacks the scorched leaf edges, large lesions, dieback and cankers observed in dogwood anthracnose (Discula destructiva).
The fungus overwinters as dormant mycelia in leaf and flower buds and stem spots. Spores are produced in the spring shortly after buds open. Spring rain showers splash the spores to bracts and young, susceptible leaves and stems. Small red-brown pinpoint spots grow to approximately 1/8 in diameter; the center dies and the dead tissue may crack fall out. Heavily infected bracts may die and drop though damage to leaves and stems is minimal. This disease rarely causes entire leaves turn brown, defoliation, or branch dieback. If this is observed later in the season, it is likely due to Septoria leaf spots which resemble dogwood spot anthracnose.
Dogwood spot anthracnose is likely to occur every year, however severity can vary dramatically from year to year. Most infected landscape trees do not require control unless there is a history of repeat, severe infections or defoliation from Elsinoe corni. Applications of propiconazole, chlorothalonil or thiophante-methyl from bud-break until most bracts have fallen from the tree will protect trees. Always read and follow the instructions on the fungicide label.
Active Ingredients include: Chlorothalonil, Propiconazole, Thiophanate-methyl
