Web Blight

You'll see browning of outer foliage in roughly circular areas on firs, with affected needles staying attached. Fine fungal webbing binds discolored needles together during moist conditions. The binucleate Rhizoctonia-like fungus is worse in Christmas tree plantations with dense spacing. Space plants for air circulation, avoid low-lying areas, and remove severely affected trees.

Avoid planting in low-lying areas with poor air drainage. Space plants for good air circulation. Remove affected tissue promptly, cutting into healthy wood. Improve air circulation by thinning dense growth and avoid overhead watering during susceptible periods. Preventive fungicide applications may help where the problem recurs annually.