Rose: Rust

categories: Flowers Ornamentals Rose Rose Diseases

revision date: 2023-02-07 12:00

Clumps or pustules of red to orange powder on the lower surfaces of leaves and corresponding yellow, orange, or brown spots on top side of leaves.
Rust on rose leaves
Photo by: R.S. Byther

Biology

Rust usually is first noticed as clumps or pustules of red to orange powder on the lower surfaces of leaves. The upper surface may also show yellow, orange, or brown spots, corresponding to the location of the pustules on the underside. Symptoms may also appear on young stems and green flower parts. Some rose varieties are tolerant of infection, while others drop infected leaves. This fungal disease can be spread by wind or splashing water and is most serious during cool, humid weather.

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 and splashing water onto plants.
  • Pick and destroy infected leaves to prevent spread of disease. Prune and destroy infected stems and flowers.
  • Rake and destroy all fallen leaves.
  • Prune old canes during dormant season to reduce amount of overwintering fungus.
  • Space plantings and prune to provide good air circulation.
  • The PNW Plant Disease Management Handbook contains a list of resistant cultivars.

Chemical Management

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

Apply fungicides during the growing season.

Approved Pesticides

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

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