Question: why are the tips of my arborvitae turning brown?
Answer: The Reason Why Arborvitae Foliage Turns Brown The combination of wind, sun, freezing temperatures, and lack of available water in winter can cause arborvitae foliage (and the leaves of other evergreens, as well) to turn brown. This happens because they are drying out. Water is the lifeblood of foliage.