Winterizing Trees and Shrubs
By Norm Mofjeld, Anoka County Extension Master Gardener
Trees and shrubs add value to our properties in many ways. In addition to the visual interest and beauty they provide throughout the seasons, they can also give us shade from hot summer days and food for eating and preserving. They require very little from us in return, but there are a few things we can do to protect them from the winter elements.
Watering: Trees and shrubs should be watered throughout the fall until freeze-up, particularly during drought conditions such as we have had the past few years. Depending on your soil, you may have to provide up to an inch of water each week. I like to set a garden hose at the base of each tree or shrub for about 30 minutes to water deeply, but you also want to avoid over-watering. Check your soil at the six-inch depth. If it is cool and moist, you are providing enough water. If you have an irrigation system, remember to continue watering your trees and shrubs after the system is blown out in the fall.
Mulching: Another good protection is to mulch about four inches deep in an area a few feet around the base of each tree, especially fruit trees. Avoid the ‘volcano’ approach and keep mulch six inches from the trunk of the tree to avoid root-girdling, which will eventually kill the tree. Mulch will help prevent frost from penetrating too deeply into the soil and damaging the roots; you can use lawn edging to keep it tidy. Cut off any suckers from the base of the trunk, and clean out weeds as well as fallen fruit which will attract insects and animals. If you are concerned about damage from deer, surround the area with a wire fence at least five feet high.
Sunscald: Caused when there is a fluctuation in temperature due to the sun warming the tree bark on cold winter days, sunscald typically damages the south or southwest side of a tree. Younger trees with thinner bark are more susceptible to sunscald, and other trees at risk include cherry, crabapple, linden, maple, mountain ash, and plum. You can protect trees by placing a white plastic guard or white commercial tree wrap around the trunk in the late fall (remember to remove it in the spring). The guard prevents sunscald by reflecting the sun and keeping the bark at a more constant temperature.
Pruning: Fall is not the right time for pruning most trees and shrubs; this typically should be done in the winter when they are dormant. However, there are some exceptions, so do your research before getting out those clippers.
Trees and shrubs are a great investment in your property. By taking some simple steps now, you will keep them healthy for many years. For more information about winterizing your trees and shrubs, read this article on the University of Minnesota Extension site: Protecting trees and shrubs in winter | UMN Extension
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