Leaf Spot Diseases
LOWVarious (Septoria, Phyllosticta, Cercospora spp.)
Overview
A broad group of fungal diseases that cause discrete spots on the leaves of deciduous trees. Most are primarily cosmetic and do not seriously harm established trees. They are most common during wet spring and summer weather. Many different fungi cause leaf spots on different tree species.
- Type
- Fungus
- Severity
- LOW
- Source
- USFS
Symptoms
Discrete round to irregular spots on leaves, spots may be brown, tan, black, or reddish, spots may have concentric rings or distinct borders, some spots may merge into larger blotches, premature leaf drop in severe cases, mostly cosmetic damage on established trees
Affected Species
Geographic Spread
Treatments
Sanitation and Cleanup
Rake and destroy fallen leaves in autumn to reduce overwintering spore load. Improve air circulation through pruning. Most leaf spot diseases do not require fungicide treatment on established trees.
Recommended Products & Tools
Helpful supplies for managing Leaf Spot Diseases. Always read and follow label directions, and confirm a diagnosis before treating.
Broad-spectrum protectant for many fungal leaf and bark diseases.
Preventive spray for needle cast, leaf spots, and blights.
Sharp, clean cuts to remove affected wood — a tree-care essential.
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Frequently Asked Questions
What is Leaf Spot Diseases?
A broad group of fungal diseases that cause discrete spots on the leaves of deciduous trees. Most are primarily cosmetic and do not seriously harm established trees. They are most common during wet spring and summer weather. Many different fungi cause leaf spots on different tree species.
What are the symptoms of Leaf Spot Diseases?
Discrete round to irregular spots on leaves, spots may be brown, tan, black, or reddish, spots may have concentric rings or distinct borders, some spots may merge into larger blotches, premature leaf drop in severe cases, mostly cosmetic damage on established trees
Where is Leaf Spot Diseases currently found?
Leaf Spot Diseases is currently active in Alabama, Arkansas, California, Colorado, Connecticut, District of Columbia, Delaware, Florida, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Michigan, Minnesota, Missouri, Mississippi, North Carolina, Nebraska, New Hampshire, New Jersey, New York, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, Vermont, Washington, Wisconsin, West Virginia. It has been reported in 38 total states across the United States.
What plants are affected by Leaf Spot Diseases?
Leaf Spot Diseases affects Red Maple, Sugar Maple, White Oak, American Elm, Flowering Dogwood. Susceptibility varies by species.
How do I treat Leaf Spot Diseases?
Treatment options for Leaf Spot Diseases include: Sanitation and Cleanup. Treatment approaches may include chemical, biological, cultural, and mechanical methods depending on the severity and context.