Black Spot Fungus Spreading: Climber as Disease Reservoir

Three-Year Black Spot Battle: Climbers Infecting Entire Garden

Climbers get Black Spot first, spread to 5 other plants over 3 seasons. Spraying, fertilizing, leaf removal failed. Climber nearly bare, others infected. Asks: treat aggressively next year or remove climber?

Black Spot Life Cycle

Spores airborne → rain/wind drives to leaves → root into tissue → kill leaf section → black mound forms → leaf drops. Control, not cure.

Prevention Protocol

1. Dormant oil + sulfur spray before leaf-out (kills overwintered spores on canes)
2. Weekly fungicide at first leaf emergence for 1 month, then monthly
3. Weather matters: fungus loves damp/humid

Color Susceptibility

Scarlet reds, apricots, yellows most prone (dry-climate genetics).

Climber Decision

If climber is highly susceptible variety, consider removal. But dormant oil protocol often controls spread without drastic measures.