Every spring, some of us are faced with evergreen trees and shrubs that have areas of brown foliage. The brown foliage we see in the spring is generally the result of desiccation caused by the sun and wind during our winter and early spring months. Water lost during this time is not readily replaced by the plant because the roots are in frozen soil. A common name for this type of damage is winter burn.
Prevention of winter burn begins with selecting plants that are hardy to your area. The next step is selecting a proper planting site. Avoid planting yews or arborvitae on the northwest side of structures unless they have adequate protection from a northwest wind. The last step is to make sure evergreens are sufficiently watered prior to the soil freezing. To help retain soil moisture and reduce root competition from grass place a three to four inch thick layer of wood mulch around your evergreens. Extend the mulch ring slightly beyond the drip line and keep mulch a few inches away from the trunk.
If hardy evergreens were selected, planted in a suitable location, and sufficient water was available throughout the growing season, there is generally no need for additional protection. If you have noticed brown foliage in the past or would like additional protection, you can construct a barrier made of burlap or a similar screening material on the south – southwest and northwest sides of your evergreens. This will help to prevent damage caused by the sun and wind. If brown foliage was previously noticed on all sides of the evergreen try surrounding it with the barrier. The barrier should be the same height or slightly higher than the evergreen or group of evergreens you are protecting. Keep the top of the barrier open for some air and light penetration.
If you do notice brown foliage this spring, wait until mid-spring before pruning it out. Even though the foliage is likely dead there may be buds that are still alive to fill in where the brown foliage was located. With proper care and a little luck your evergreens should be nice and green this spring.
If you have questions about protecting your evergreens please call me at the University of Minnesota Extension office, Clay County at 218-299-7338 or by email [email protected] Check out our website at https://local.extension.umn.edu/local/clay The University of Minnesota Extension is an equal opportunity educator and employer.