Bacterial Leaf Spot and Stem Canker
Xanthomonas hortorum pv. hederae
2 host plants
Last updated
Lesions on leaves extend to stems, forming cankers that girdle shoots. Prune well below symptoms and sterilize tools. The pathogen (Xanthomonas hortorum pv. hederae) favors moist conditions and enters through wounds or natural openings. You are most likely to see symptoms during the growing season when conditions shift between wet and warm. On susceptible hosts, the damage can progress quickly if left unchecked.
Prune out cankered branches at least six inches below visible symptoms, making cuts into healthy wood. Sterilize your tools between cuts. Canker pathogens typically enter through wounds, so minimize pruning injuries and avoid working on trees when bark is wet. Maintain tree vigor through proper watering and avoid stress from drought or compacted soil, which makes trees more susceptible.
Quick Reference
Management
Warm humid weather; overhead irrigation; crowded nursery conditions; mechanical wounding during handling
Cultural Controls
- Prune out and destroy infected branches. Plant disease-free nursery stock. Carefully inspect plants arriving from New Jersey or from the Southern States where this disease is a problem.