Rose: Black spot

categories: Flowers Ornamentals Rose Rose Diseases

revision date: 2023-02-07 12:00

White rose with black spot on leaves.
Rose black spot on leaves
Photo by: R.S. Byther

Biology

Black spot is a very common fungal infection of the leaves and canes of roses. Round black leaf spots (sometimes with fringed or feathery edges) may be accompanied by leaf yellowing and leaf drop in susceptible varieties. Canes often display small reddish-purple to black spots. High humidity, rain, and overhead watering contribute to the development of this disease. Black spot is spread by splashing water.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Avoid overhead watering. If overhead watering is necessary, water during the morning hours so leaves can dry quickly.
  • Space plantings and prune to improve air circulation. Good air circulation limits disease development.
  • Prune and destroy diseased leaves and canes. Do not compost diseased material.
  • Rake and destroy all fallen leaves from under plants.
  • Plant resistant varieties. Your county extension agent or WSU Master Gardeners can make recommendations.

Chemical Management

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

  • Apply frequently in wet spring weather and occasionally in summer.
  • Copper fungicides may cause some discoloration of foliage or blooms.

 

Approved Pesticides

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

Additional Images