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Black Tar Spot

MODERATE

Rhytisma acerinum

Overview

Black Tar Spot observed in the wild. Research-grade iNaturalist observation.

Type
Fungus
Severity
MODERATE
Source
iNaturalist

Symptoms

Geographic Spread

Treatments

Fungicide Application

Chemical TreatmentEffectiveness: HIGH

Apply systemic or contact fungicide at the first sign of infection. Repeat applications may be needed during wet weather. Follow label rates and timing.

Sanitation and Pruning

Cultural PracticeEffectiveness: MODERATE

Remove and destroy all infected leaves, branches, and fallen debris. Improve air circulation by thinning dense canopy growth. Sterilize pruning tools.

Soil and Moisture Management

Cultural PracticeEffectiveness: MODERATE

Ensure proper drainage, avoid overwatering, and apply mulch to reduce soil splash. Many fungal pathogens thrive in persistently wet conditions.

Recommended Products & Tools

Helpful supplies for managing Black Tar Spot. Always read and follow label directions, and confirm a diagnosis before treating.

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Frequently Asked Questions

What is Black Tar Spot?

Black Tar Spot observed in the wild. Research-grade iNaturalist observation.

What are the symptoms of Black Tar Spot?

Where is Black Tar Spot currently found?

Black Tar Spot is currently active in New Jersey, Ohio, Massachusetts, Pennsylvania, New York, Minnesota, Michigan. It has been reported in 7 total states across the United States.

How do I treat Black Tar Spot?

Treatment options for Black Tar Spot include: Fungicide Application, Sanitation and Pruning, Soil and Moisture Management. Treatment approaches may include chemical, biological, cultural, and mechanical methods depending on the severity and context.

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