Boxwood: Leaf spot

categories: Boxwood Boxwood Diseases Ornamentals Shrubs

revision date: 2022-11-30 12:00

Boxwood Pseudonectria leaf spot.
Boxwood Pseudonectria leaf spot
Photo by: R.S. Byther


Boxwood leaf spot is caused by fungi which survive in fallen, diseased leaves beneath the plant. Leaves develop discolored spots and may turn tan or brown from the margins and tips inward. Small, black fruiting bodies of the fungus often appear on the discolored spots or the underside of the leaves. Leaf spot is favored by wet, humid weather and damp planting conditions.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Prune and destroy infected and dead plant parts.
  • Collect and destroy dead leaves under plants and in branch crotches.
  • To reduce likelihood of infection, avoid overhead watering and space plants to provide good air circulation.

Chemical Management

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

  • Make fungicide applications in spring before new growth starts.

Approved Pesticides

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