Winter drying occurs when moisture is lost from the foliage and cannot be replaced because the soil around the tree roots is frozen. Warm winds contribute to drying out the buds and foliage that extend above the snow level.
Winter burning occurs when the temperature changes suddenly. This is common on the south side of trees, where exposure to the sun is greatest. Winter burning and winter drying often occur together.
Trees grown outside of their native range are more susceptible to winter injury than native plants. Ornamental plantings may be heavily damaged, especially if the cultivars have been selected for a desired shape or appearance rather than for hardiness. Scotch pine, junipers and cedars are often damaged. If your trees are damaged, don’t be too quick to cut out the brown foliage. Wait several weeks to see what shoots green up and bud out, then prune the dead portions.
To reduce winter injury to trees, ornamental trees should be well-watered in the fall and mulched to prevent the soil from completely freezing in the rooting zone. Susceptible trees can be wrapped in burlap to reduce loss of moisture from the foliage. When choosing planting locations, avoid locations where sudden temperature changes may occur. Select cultivars that are hardy in the conditions of your local area.
Salt damage occurs when foliage is burned by salt splashed directly onto the foliage or by salt absorbed through the roots. Damage is usually greatest on the side facing a roadway, or in areas where the drainage pattern causes accumulation of de-icing salts. The affected foliage will fall off in the spring, and the new growth may make the tree appear otherwise healthy. However, the trees will grow more slowly and remain stunted, and eventually might be killed by prolonged exposure. White pine is extremely sensitive to salt damage, and red pine is also injured. As with winter drying and burning, don’t be too quick to remove the “dead” shoots.Often, salt injury does not kill the buds and the new growth may be healthy.
If you fear the soil around your trees has taken in too much road salt over the winter, flush the soil with water in the spring when it thaws. This should send salts beyond the trees’ root zones, where they can’t harm the trees. Also avoid de-icing salts. Use coarse sand to help make sidewalks and driveways less slippery. If you must use salt, use as little as possible. Keep your plants and trees healthy. A healthy plant is better equipped to survive salt spray and accumulation. Use barriers. Protect sensitive plants with plastic fencing, burlap or snow fencing.
Damage from the wrath of winter can be avoided or at least reduced by some steps of prevention.