By Melissa Koesler
Garvin County Extension Director
Agriculture/4-H Youth Development Educator
A group of plants that often experience winter damage are the broadleaf evergreens such as hollies and boxwood. Water loss can cause severe damage to broadleaf evergreens during winter when high winds or temporary warm weather causes a plant to give off an unusually high amount of moisture.
When this water loss occurs at times when the ground is frozen, roots cannot take up moisture to replace lost water. The result is a browning or burning of the foliage.
Various management practices may help to prevent winter damage.
Make sure the plants enter the dormant season in a healthy and vigorous condition with adequate soil moisture. Check to see that the center of the plant is free of dead leaves and other debris. And be sure to continue watering during the dry winter months.
Monitor weather conditions and water during extended dry periods or about one to two times per month.
Water only when air temperatures are above 40 degrees F. Apply water at midday so it will have time to soak in before possible freezing at night.
Mulch the plant with wood chips to reduce water loss from the soil. Mulch also protects the plant by preventing rapid temperature changes at the soil surface.
Boxwoods seem to be more susceptible to winter damage.
Boxwoods placed in sites exposed to winter winds tend to experience more damage. Provide wind protection for plants in exposed situations by creating a simple wind break.
Use snow fences or stretch burlap between stakes or over a lattice frame set next to the boxwood. Or you can stick pine boughs in the ground around plants to form a wind break.
When planting boxwoods, it is best to avoid exposed, windy sites.
Large boxwoods and other evergreens prone to ice damage may be protected by wrapping the outer branches with strong nylon cord.
Tie the cord securely to a low branch, pressing the boughs upwards and inward; wrap cord in an upward spiral around the bush, having cords 8 to 10 inches apart. Have cord tight enough to prevent breakage from excess weight of snow or ice, but not tight enough to exclude air circulation around the plant.
(Information provided by David Hillock, Associate Extension Specialist, Consumer Horticulture.)