The winter is hard on trees, even those that are accustomed to cold climates. Stress caused by cold, drought, pests and branch breakage can take its toll. While you can't do much about the weather and icy temperatures, you can take steps to lessen their impact.
Keep Trees Clear of Snow
After a heavy snow, brave the cold and do your best to remove as much snow as possible from your trees' branches. Excess snow can cause branches to bend — which can cause damage — as well as break. Too much snow sometimes can even make the trees themselves bend and break. Remove snow using a broom or a similar tool to gently remove snow from tree branches. Use a broom in an upward, sweeping motion. You can also shake or tap tree trunks to remove snow, however, don't shake the branches — this may cause them to break. If the snow is frozen on the branch and will not brush off easily, it is best to let it melt naturally to avoid damage to the tree or shrub.
Fight Winter Drought
Wind and a lack of liquid water can cause drought in the winter months. Once the ground freezes, tree roots can't absorb any more water. While it might seem strange to water trees in cold weather, it should be done if you didn't do it earlier in the fall, as tree roots often do not get enough moisture after the ground is frozen for an extended period of time. While often there isn't much to be done about drought once winter really kicks in, on a milder day when the ground isn't frozen, you can try watering around the base of trees.
Keep Critters Away
The weather isn't the only thing that trees contend with during winter. Squirrels, rabbits, mice and other animals, such as deer, can damage bark, limbs and leaves.Place wire mesh or chicken wire around the base of the tree about 6" from the tree like a fence to prevent most rodents from getting their teeth on the bark. You may want to apply a squirrel repellent to stop squirrels from climbing and damaging trees. Consult your local True Value expert for the best product for the job.
Prune in Late Winter
Winter is a great time to prune most deciduous trees. Because they're dormant in winter, fruit, flowering and shade trees can be pruned now. When pruning large limbs, always undercut first — cut from the bottom up, one-third of the way through the limb, then finish by cutting from the top. The undercut keeps the limb from splitting and breaking off, preventing damage to the trunk. Don't cut flush to the trunk. It's the collar or enlarged base of a branch that produces the hormones to help heal wounds, so it's important to keep the collar intact.