Identifying and Treating Rose Rust

Raised, mustard-yellow, powdery-but-firm spots on leaf undersides are classic symptoms of Rose Rust, a fungal disease favored by damp, cool springs. Some cultivars are highly susceptible.

Treatment

• Spray with a fungicide labeled for rust (e.g., Ortho Rose Pride), covering leaf undersides thoroughly.
• Treat soil around base to kill overwintering spores.
• Remove and destroy infected leaves.
• Improve air circulation and avoid overhead watering.

Long-Term Outlook

If rust recurs annually, the variety is prone to it. Consider replacing with a resistant cultivar. Good sanitation reduces severity.