Stigmina Blight

Port Orford cedar (Chamaecyparis lawsoniana) shows needle yellowing and defoliation, especially on lower and interior branches. Pseudocercospora thujina causes this fungal blight. Plant seedstock from resistant coastal provenances. Remove severely affected trees to protect nearby plants. Pruning lower branches may help, but no chemical controls are available or recommended.

Plant trees from seed sources found to be more resistant to the disease. Remove affected foliage at the base of trees, however, it is not known if this will be beneficial in disease management.