Winter is a time for rest for our trees and shrubs, but there are things we can do to keep them warm and protected throughout the cold weather so they are in optimal condition come spring.
Some examples of cold damage to trees and shrubs are sun scald, dieback, frost heaving and root injury. Sun scald happens when the bark on a tree heats up on chilly winter days when the sun is hitting it, which prompts bark tissue to grow, but then suddenly die once the sun goes down and the colder temperatures return. There are several species of tree where this is more common, but it also is more prevalent in younger trees because as trees age, their bark becomes harder which makes them more protected from the problem.
There is a solution to sun scald and that is simply to wrap the trunk of the tree with a tree wrap, use a plastic guard around the tree or just wrap the trunk in a light coloured material. Any of these solutions deflect the sunlight and protect the tree. It is recommended that newly planted trees be wrapped for their first two winters and thin barked trees for at least their first five.
We think that evergreens are hardy enough to withstand anything Mother Nature can throw their way, but they too can be damaged by the cold. The big thing with evergreens is they dry out when they lose water. If there are sunny winter days or a lot of wind in a winter, this can happen a lot faster. A simple solution is to ensure those evergreens are watered well in the fall so that they can retain some of that water and alleviate the problem of drying out. Also making a screen around them to ward off the wind or wrapping them in burlap can help. Snow is also a great insulator, so you can shovel some of it around the base of your evergreens to keep them warm and happy through the winter months.
Lastly, make sure there are no cracks in the soil around your trees and shrubs and that the root zone is covered with at least 6″ of mulch–you can also use pine needles and bark for a mulch if you need to, just keep the bottoms of those trees protected and insulated. Come spring you’ll be happy you took the time to winterize your trees!