The south and west sides of several yews turned brown in early spring. Why did this occur and what can be done to prevent it?
Browning of yews in late winter or early spring is usually the result of desiccation injury. Evergreen foliage continues to lose moisture during the winter months, particularly on windy or sunny days. However, once the soil freezes, the plant’s roots are no longer able to absorb moisture. Foliage exposed to the drying effects of the sun and wind may eventually dry out and die. While desiccation injury occurs during the winter months, the browning of the needles often doesn’t occur until late winter or early spring.
To prevent desiccation injury, deeply water susceptible evergreens in fall if the soil is dry. Continue watering on a regular basis until the ground freezes in winter. Watering is especially important to evergreens planted within the past two or three years. To help conserve soil moisture, apply a 2- to 3-inch-layer of mulch, such as wood chips or shredded bark, around each evergreen. Moisture loss can also be reduced by placing a burlap screen around susceptible evergreens in fall. Anti-desiccants may also be helpful.