Treating Blackened Holly Leaves: Leaf Blight vs. Tar Spot

Identifying the Disease

A homeowner has holly bushes with blackening leaves and twigs spreading over months, affecting one plant while a neighbor remains healthy.

Diagnosis and Management

Ed Gulliksen identifies two possibilities: Holly Leaf Blight (affects leaves and branches) or Holly Tar Spot (primarily foliage). The branch involvement suggests leaf blight. No chemical cures exist.

Cultural Control Strategy

• Prune affected areas – Remove all blackened tissue
• Sterilize tools – Bleach between cuts to prevent spread
• Fertilize for vigor – Stimulate new healthy growth
• Avoid foliage wetting – Redirect sprinklers; wet foliage promotes disease

Sanitation and plant health are the primary defenses against these fungal diseases.