Rust, Black Spot, and Aphids on Climbing Roses in San Ramon, CA

A zone 9 San Ramon gardener found rust on Don Juan climber, then black spot and aphids on nearby Iceberg climber and carpet roses after removing infected leaves (leaving bare canes).

Don't Panic—Roses Regrow Leaves Easily

Defoliation from disease removal is temporary. Roses readily produce new foliage when conditions improve. Your plants aren't dead.

Disease Management

Rust (Don Juan): Apply rose fungicide (myclobutanil, propiconazole, or neem oil) per label. Don Juan is rust-prone—consider replacement if chronic.

Black Spot (carpet roses): Same fungicides work. Clean up ALL fallen leaves—spores overwinter in debris.

Aphids (all): Blast off with strong water jet daily for 3 days. Ladybugs will follow. No insecticide needed.

Critical Cultural Fixes

• Clay soil is GOOD for roses—amend with 1/3 compost + 1/3 coarse sand for drainage
• Water at soil level ONLY—wet foliage = fungal highway
• Space for air flow—thin crowded plantings
• Morning sun essential—dries dew fast

Fertilizer + Pesticide Combo?

NO. Apply separately. Fungicide for diseases. Insecticidal soap for aphids ONLY if water blast fails. Liquid fertilizer on separate schedule.

Source Quality Matters

Nursery plants often carry latent diseases. Don't blame yourself—replace chronically problematic varieties with resistant ones (Knock Outs, Drifts, Earth-Kind winners).