Angular Leaf Spot
Pseudomonas syringae pv. syringae (bacterial form, most common on Magnolia); ...
1 host plant · Bacterial
Last updated
Water-soaked lesions with angular margins develop on leaves along veins. This bacterial disease spreads by rain splash. Avoid overhead watering and space plants.
Leaf spot and blotch diseases are primarily cosmetic on established plants, though repeated years of heavy infection can weaken them. Rake up and remove fallen leaves to reduce the spore load going into the next season. Avoid overhead watering that splashes spores from the ground onto lower leaves. If the problem is severe, protective fungicide sprays during spring leaf emergence can help, but sanitation does more than chemistry for most leaf spots.
Quick Reference
Management
Bud break through early summer; secondary cycles possible during cool wet weather.
Cool wet spring weather (50-70°F) with extended leaf wetness; frost injury increases susceptibility.
Cultural Controls
- Avoid overhead irrigation; use drip or soaker hoses.
- Prune to improve air circulation in the canopy.
- Remove and destroy fallen leaves and infected twigs during dry weather.
- Avoid pruning during wet weather; sterilize tools between cuts.