To properly protect your plants from the harsh winter during those cold months you will need to mulch: don’t underestimate the importance of mulching and, depending on the individual plants, some will be heavily mulched, and some lightly mulched. You’ll need to know what is required for each species of plant you’ll be growing.
For instance, if you put too heavy mulch on perennials it can be harmful because it can rob them of the sun and the air, and also you’ll be providing a nice cozy winter home for those rodents that will eat your plants. The deciduous and evergreen trees and shrubs, especially the ones you have recently planted, are really benefited by heavy mulch.
To get the most benefit from the winter mulch there just has to be sufficient moisture in the soil. If you have less rainfall than usual in the autumn months you’ll want to thoroughly water the beds, shrub borders, and evergreens before winter comes around.
Wait till the ground is frozen and then apply the mulch. Remember that the purpose of the mulch is not to keep the plants warm but to prevent the ground from heaving because of alternate freezing and thawing. Always avoid a wet, closely packed mulch. Snow is also a wonderful winter mulch if you live in an area where snow seems to remain on the ground for long periods of time. If you have continuous snow you won’t even need the winter mulch.
When winter mulching trees and shrubs be very careful not to have a mass of wet material against the trunks or the stems. This protects many of the main feeding roots.
Now in addition to the winter mulching you can do other things to prevent injury to your plants. Remember, plants are hardy in their own habitat. When you move them to a colder climate they need winter protection. Notice the native plants around you: they just thrive because they grew
there as native plants, but those that you bring from another area to plant will need winter protection.
Evergreens are actually more susceptible to winter injury than deciduous trees and shrubs as they are have the ability to lose moisture through their leaves in winter as well as in summer, and unless that moisture can be replaced, browning of the leaves and drying of the branches or of the whole plant may be the result. Be sure to water well before winter if you have had a dry fall.
There are so many ways to protect plants when you are doubtful of their ability to withstand winter months, but just remember that in most cases the total aim is not to prevent freezing, but to shield the sun from the sun and the wind. Straw mats make really good windbreaks and can be saved from year to year.