We live in USDA Hardiness Zone 5 and have some Zone 6 pockets. This means that, although we aren’t in the coldest zone, many of our trees and shrubs need extra protection from winter’s extremes.
Tender trees and shrubs, especially young trees that you just planted this year, may need a burlap coat. Wrappings are easy to install. Just drive poles into the ground around the perimeter of the tree or shrub, wrap with burlap and staple it to the poles. Be sure to keep the top open to moisture and sunlight. Wrapping may also be needed for evergreens planted close to the road to protect them from road salt spray.
Besides protecting your trees and shrubs from desiccation and salt spray, wrapping can reduce the chance of deer damage since deer will have a tough time getting to the tree.
Deciduous trees with thin, smooth bark can be damaged by sunscald and frost cracking in the winter. Sunscald is caused by the winter sun heating the trunks to the point that the sap begins to flow. When the sun disappears and the temperature plummets, the sap freezes quickly, killing the surrounding tissue, or causing long vertical cracks in the bark. The bark can be kept at a more constant temperature by installing tree wrap or plastic tree guards that you can buy at your garden center or home store.
As long as you are wrapping trees, you might consider wrapping tree trunks with hardware cloth to cut down on critter damage. While deer like to browse on tender branches, mice, rabbits and voles prefer to chew the bark on the lower parts of the trunk. Hardware cloth is a flexible screening that you can buy at hardware stores and home centers. It can be attached to the same posts as burlap or to its own posts. It works best if it isn’t touching the tree bark.
That is just too wickedly cold. There are many plants that I miss from the Los Angeles region that do not tolerate even our mild winters, which is fine, but I do not think that I would like weather that is too cold for trees as familiar as redwoods. The coastal redwood tolerate the frost that they get up near Oregon, but on the Olympic Peninsula in Washington, they get tip burn, which makes them look like they get shorn. They do not tolerate the weight of snow either.