How to Winterize Trees & Shrubs: A Step-by-Step Guide

As the temperatures drop and the frost arrives, homeowners across Canada dig out the pruning shears and start putting their autumn gardens to rest for the season. But your delicate flowerbeds and vegetable gardens aren’t the only greens that need protecting from harsh Alberta winters.

Trees and shrubs are just as susceptible to the elements as other foliage, so winterizing your garden should include giving your branches some love, too. Follow our step-by-step guide for how to winterize trees and shrubs so yours stay healthy throughout the cold season. Plus, we’ve included tips for protecting some of the most commonly found trees in the province.

Step 1: Aerate & fertilize the soil

When planning your winterization strategy, start from the ground up. Carefully loosen compacted soil to increase its capacity for drainage once the snow piles up. This prevents the roots of your tree or shrub from being suffocated.

Next, consider fertilizing trees and shrubs that don’t grow in nutrient-rich soil. Be sure to use a fertilizer tailored to your tree. For example, if it’s one that you’ve recently planted, steer clear of using fertilizer with too much nitrogen since it can do more harm than good. When you go to buy your soil at a home and garden store, speak to an associate for an idea of what type of soil your trees and shrubs need.

Step 2: Insulate the roots

After tilling and fertilizing the soil, turn your attention to blanketing it for the season. Insulating your tree or shrub’s root system is crucial to ensuring their protection from the cold.

To winterize your trees’ and shrubs’ root systems, spread a hefty layer of mulch on the ground as far as the tree’s branches spread. Not only does this create a warm and cozy winter blanket, but it also helps prevent weeds from growing. Just make sure that the mulch doesn’t touch the tree trunk itself or pile up around the trunk in a dome. Aim for an even layer all around.

Step 3: Prune branches & bark

Just like you cut back your flower beds before the freeze arrives, you’ll also want to prune dead and damaged branches that could harm your trees during the winter. Completely remove any branches that clearly are dead or rotting—these provide food and shelter for unwanted pests. Next, lightly trim branches that will touch the ground under the weight of heavy snow. Branches that sit on the ground are far more likely to pick up moisture rot and disease.

Be mindful while you prune; you want to preserve and protect as many of the healthy branches as possible. If you absolutely must make a cut, make sure you’re using a sharp, clean pair of shears. Clip the branch above and below the branch collar (the slightly bulbous area where the branch meets the tree trunk) instead of trying to remove the branch in one cut. The Alberta Arborists have a  on all the dos and don’ts of tree-pruning you can reference when you winterize your trees.

Repurpose for the Season

For evergreens you have heavily pruned or cut down, consider using the foliage in your holiday decor.

Place freshly pruned branches in vases with water to enjoy their fragrance, or use twine and wiring to make a wreath to hang on your door. Use smaller trimmings as accents on holiday wrapping or put them in bowls with pinecones and ornaments as festive centerpieces.

Step 4: Don't forget to water

Regularly watering your flower, fruit and vegetable patches becomes second nature to Albertan gardeners…but how often do you think to water your trees? Just like the other flora in your landscape, your trees need to stay hydrated to take in nutrients from the soil and keep their root systems healthy.

When winter arrives, frozen soil prevents your plants from drinking in the water they need. Giving your trees and shrubs a few deep watering sessions prior to the first hard freeze will help them store up that crucial well of hydration.Ěý a “5+5 rule” for winterizing newly planted trees: five gallons of water as a base, plus another five gallons for every inch of your trunk’s diameter.

Step 5: Wrap vulnerable trees  & shrubs

Another way to winterize trees and shrubs is to wrap them in burlap before the first snow. This protects them from a variety of ailments, the most common being “winter burn.” Winter burn is characterized by patches of brown, dry, brittle needles on the sides of your evergreens. Winter burn occurs when your tree receives lots of sun but can’t pull enough moisture from the ground to counter it (another reason why watering is important!). Young trees are especially vulnerable to both winter burn and sun scald, which damages the trunk in places where the tree’s heartwood is exposed to the freezing temperatures.

Wrap the trunks of trees that have smooth bark, as well as those that are young or freshly planted. If you have evergreens and shrubs that are a manageable size, wrap the entirety of the foliage in burlap to protect the needles from ice, wind, heavy snow and sun.

If wrapping the tree or shrub itself is too unwieldy, you can build a burlap screen around your plant to shield it from the winter winds. To build the screen, place stakes in the ground around your trees and shrubs. Then, attach a sheet of light wire (chicken wire works great) to the stakes. Finally, secure the burlap screen to the wire using wire twist ties or bag ties.

Winterizing Alberta Trees

Just as various flowers require different levels of sunlight to flourish, trees and shrubs need specialized care, too. Deciduous trees have different needs than evergreens; young trees adapt differently to the winter elements than old; delicate shrubs need more care than heartier ones.

Depending on what your landscape is made up of, your foliage may need just a few or all of the methods outlined above. Below are a few examples of how to winterize trees and shrubs commonly found in Alberta.

Dwarf Alberta Spruce

With its petite size and vibrant needles, there’s a reason this beautiful tree carries the province’s name. However, it’s also a relatively delicate evergreen that requires protection against the winter elements.

In addition to planting your Alberta spruce in a protected location, you can winterize this tree by cutting away any dead or ground-touching branches, giving it a deep water and wrapping it entirely in burlap to save its needles from winter burn and winds.

White Birch

The birch is widely known for (and identified by) its beautiful, thin, white bark. But if you’re not careful, sun scald can severely damage the bark of younger birches throughout the winter months. Winterize these trees by wrapping the trunks of your birches for at least the first five winters after you plant them. Mature birch trees are heartier, and their reflective white bark should protect them from sun scald.

Water your birch tree’s trunk and roots, then spread a good layer of mulch around the area to insulate it from the cold. If the winter is particularly dry and cold, you may need to water your birch periodically throughout the season.

Honeysuckle Bush

During the warmer months, the smell of honeysuckle blossoms is simply divine. It would be a shame to lose your shrub to the harsh Canadian winter!

Prune your honeysuckle bush of any dead branches and fertilize the soil before spreading an insulating layer of mulch over the root bed. Lightly wrap your shrub in burlap or a specially shaped shrub jacket.

With this guide, you should be able to keep your Alberta trees and shrubs healthy and warm for the season.Ěý