Diagnosis
Diagnose: Arborvitae Winter Burn
Use these observations to decide what to check next.
Winter burn, meaning foliage that dried out while the roots were in cold or frozen soil.
Browning concentrated on an exposed face, especially beyond the snow line, is consistent with winter injury. That pattern is a clue rather than proof, so the soil, road-salt exposure, and timing matter too.
Ragged browsed twigs suggest deer damage. Silk cases warrant a closer look for arborvitae bagworms, while unusual twig lesions or spreading dieback may need a diagnostic assessment; more than one problem can affect a hedge.