Foliage at the base of branches throughout the canopy turns brown, typically during summer or fall. Needles may drop prematurely. Flagging on arborvitae or western red cedar may be caused by several factors, including injury to roots, drought, and hot weather. Trees usually recover in spring.
Solutions
Protect trees from injury. Avoid disturbing the soil around the roots. Provide adequate irrigation during prolonged drought.
The pesticide information on this page may become out of date as products and active ingredients change or become unavailable. Some of the pesticides listed are only available for use by licensed pesticide applicators. No endorsements of named products are intended, nor is criticism implied of products not mentioned.
