Blackberry Rust

Orange pustules form on cane undersides and yellow spots on leaves. Remove infected canes and improve air circulation. You are most likely to notice symptoms during periods of active growth, particularly when moisture levels favor pathogen development. Early recognition is your best advantage: the sooner you identify the problem, the more effective your management options will be.

Rust fungi often need two different host plants to complete their life cycle, so identifying and managing the alternate host can break the cycle. Remove heavily infected leaves and dispose of them away from the garden. Improve air circulation to speed leaf drying after rain. Fungicide applications are most effective as preventive treatments before symptoms appear; once pustules are visible, the current infection cycle is already underway.