Lower Stem Canker

Douglas-fir develops cankers on lower stems in some conditions. Detailed information on this canker type remains limited in current literature. Avoid creating wounds on trees, practice good sanitation during pruning, and maintain tree vigor through proper culture and irrigation.

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.