Volutella Leaf and Stem Blight (Canker)
Pseudonectria buxi
4 host plants · Fungal
Last updated
This profile synthesizes data from multiple published sources. Expert field review is in progress.
Boxwood branches die back with leaves turning light-green-yellow and tan, plus pink spore structures on lower leaf surfaces. Pseudonectria buxi fungus infects through wounds or winter injury. Prune out dead branches, remove dead leaves from crotches, and maintain good air circulation. Avoid high humidity and plant in well-drained soil. No resistant cultivars are available.
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
Fall through spring (October-May). Especially in cool damp growing conditions.
Cool wet conditions (10-20°C / 50-68°F); rain splash and leaf wetness drive infection.
Cultural Controls
- Prune out and burn dead branches.
- Remove dead leaves from crotches areas inside the canopy.
- Minimize wounding especially when new growth is present.
- Maintain good air circulation and drainage.
- Avoid high humidity (>85%) for long periods.
- Grow plants in well-drained media or soil with a pH between 6.8 and 7.5.