Photinia: Leaf spot (Diplocarpon)

Biology

Fungal leaf spot of photinia is characterized by the presence of red to purple spots on the leaves. The spots are small at first, but soon enlarge and develop brown to grayish necrotic centers. Small dark fruiting bodies of the fungus can sometimes be seen in the center of the spots. Severely infected leaves may drop, sometimes resulting in considerable defoliation. The disease can be spread by splashing water and overwinters on diseased plant tissues. New growth is particularly susceptible. In western Washington, photinia may develop a physiological leaf spot that resembles fungal leaf spot.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

• Plant in full sun.
• Space plantings and prune to improve air circulation.
• Clean up and destroy fallen leaves.
• Avoid overhead watering, or limit it to times when foliage can dry quickly.
• Avoid summer pruning, which promotes a flush of susceptible new growth.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

• Use in early spring as young shoots develop.
• Homeowners should not make foliar applications to trees over 10 ft tall.
• Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.

Approved Pesticides

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.

• Bonide Fung-onil Multi-Purpose Fungicide Concentrate
  Active ingredient: chlorothalonil [EPA registration number: 60063-9-4]
• Bonide Infuse Systemic Disease Control
  Active ingredient: propiconazole [EPA registration number: 100-773-4]
• ferti-lome Liquid Systemic Fungicide II R-T-Spray
  Active ingredient: propiconazole [EPA registration number: 53883-184-7401]
• GardenTech Daconil Fungicide Concentrate
  Active ingredient: chlorothalonil [EPA registration number: 67572-82-71004]
• Monterey Liqui-Cop Copper Fungicidal Garden Spray
  Active ingredient: copper-ammonia complex [EPA registration number: 54705-7]
• Ortho Max Garden Disease Control Concentrate
  Active ingredient: chlorothalonil [EPA registration number: 239-2522]
• Spectracide IMMUNOX Multi-Purpose Fungicide Spray Concentrate
  Active ingredient: myclobutanil [EPA registration number: 9688-123-8845]
• This list may not include all products registered for this use.