Rosa gallica · Shrub
Blackspot: Remove fallen leaves in autumn and apply a fungicide or lime sulphur spray in early spring.
Powdery mildew: Improve air circulation by pruning and treat with a sulphur-based fungicide or milk spray.
Rose rust: Prune out affected growth and apply a systemic fungicide at the first sign of infection.
Aphids: Squash by hand, blast with water, or use insecticidal soap for heavy infestations.
Crown gall: Cut out galls with sterile tools and destroy infected material; avoid replanting roses in affected soil.