Gardening Tips and Highlights
Prevent Winter Burn on conifers and shrubs
by Christine Yesko
Winter Burn is a common problem of evergreens including those with broad leaves (boxwood, holly, juniper), needles (fir, hemlock, pine, spruce, yew) and arborvitae, cypress, and juniper grown in open, unprotected locations and exposed to severe winter conditions. Winter burn can be so severe that affected plants may die and/or require replacement.
Here is what Winter Burn looks like: The foliage will start to brown at the tips of branches with it progressing inward toward the center of the plant. Foliage facing south, southwest or west is most often affected. In extreme cases, entire plants can brown and die.
There are many factors that can contribute to winter burn. In general, plants with shallow or poorly-developed root systems that do not efficiently take-up water are prone to winter burn. Warm fall temperatures that delay the onset of plant dormancy can also contribute to winter burn. Thus, plants are not prepared for the rapid onset of freezing winter temperatures and as a result damage to foliage occurs.
Strong winter winds can lead to additional water loss-making winter burn more severe. Exposure to salts used to deice roads, driveways, and sidewalks can make plants more prone to winter burn injury.
Avoid problems in the future by planting the right plant in the right place. Buy plants that are rated as cold hardy for your location and soil conditions. Don’t plant shade-loving cold-hardy marginal plants in sunny, windy areas. Do not prune evergreens in late summer or early fall.
Late season pruning may encourage a flush of new growth that will not harden off properly before winter. Plants that are well-hydrated are less prone to winter burn. Established evergreens should receive approximately one inch of water per week and newly transplanted evergreens up to two inches of water per week during the growing season up until the soil freezes in the fall or there is a significant snowfall.
Protecting plants with burlap, canvas, snow fencing or other protective materials to create barriers protect plants from winter winds and the sun. Remove the barrier material promptly in spring.
Information for this article was obtained from Klein’s Newsletter.