With climate change, winters in Eastern Cabada have become milder overall. But does this mean cold-sensitive plants are now more likely to survive? Should you still protect your trees and shrubs during winter?
This article answers these questions and offers practical tips to help your plants get through the cold season.
Understanding Eastern Canada’s Winter Climate
Winter in Ontario, Quebec or the Atlantic Provinces isn’t just about snow and cold. It also brings thaw periods, rain, ice, strong winds, and freezing rain.
These fluctuations can be challenging, but hardy plants have developed a range of adaptations to cope with them. One of the most important is dormancy.
While winter conditions can cause damage, they rarely threaten well-adapted plants. However, less hardy species are more vulnerable.
This is why choosing plants suited to your hardiness zone is essential. For more information, see our article on Hardiness Zones.
When Should Winter Protection Be Installed and Removed?
Install winter protection after the first hard frosts and before the ground freezes, while stakes can still be placed easily.
Ideally, deciduous trees should have already dropped their leaves. As a general rule, it’s better to install protection slightly late rather than too early.
A practical approach is to install stakes first, then add protective fabric once colder temperatures settle in. Installing protection too early can interfere with cold acclimation.
In spring, remove protection in late March or early April. Remove it before temperatures rise too much to prevent mould caused by excess humidity and poor air circulation.
Choose a cloudy day—direct sunlight can damage buds that are not yet fully hardened.
Which Plants Need Winter Protection?
Despite milder winters, most hardy plants do not require winter protection.
However, protection is recommended in the following situations:
- During the first winter after planting;
- For young trees;
- For plants at the limit of their hardiness zone;
- For plants exposed to strong winds, road salt, snowblower spray, or heavy snow.
Winter Protection for Young and Newly Planted Trees
Here are best practices for protecting young trees:
Against Cold
- Apply a thick mulch layer during the first winter to protect roots from freeze-thaw cycles;
- Sensitive species such as maples, beech, buckeye, willows, and lindens may develop frost cracks. Protect trunks with burlap or tree wrap.
Against Rodents
- Protect trunks with perforated plastic guards to prevent bark damage.
Winter Protection for Mature Deciduous Trees
Against Snowblower Damage
- Install temporary wooden barriers around trunks.
Against Rodents
- Use plastic trunk guards.
Winter Protection for Conifers
Against Wind and Cold
- Apply about 10 cm of mulch;
- Install stakes and wrap with burlap to protect from dry winter winds.
- Alternatively, use rose cones, ensuring that a few ventilation holes are added to allow for proper air circulation.
Against Road Salt
- Install a barrier (stakes or snow fence) and attach protective fabric, ensuring it does not touch foliage.
Against Heavy Snow
- Use protective netting to prevent branch breakage.
Winter Protection for Shrubs
Against Snow Load
- Tie branches or cover shrubs with netting after leaf drop.
Against Wind and Cold
- Protect less hardy shrubs with burlap or geotextile barriers;
- Use rose cones for smaller plants.
Winter Protection for Perennials
- Remove diseased material, but leave healthy stems to trap insulating snow;
- Most hardy perennials require no protection;
- Mulch less hardy species with leaf litter.
Winter Protection for Hedges
Hedges are especially vulnerable to road salt and snowblower spray. Installing a snow fence is highly recommended.
For cedar hedges, proper pruning helps reduce snow damage. See our article on cedar hedge care.
Can Container-Grown Trees and Shrubs Survive Winter?
Growing trees in containers is more challenging, especially for less hardy species. Roots are more exposed to freezing and freeze-thaw cycles.
However, overwintering is possible with proper care:
- Choose hardy species;
- Use larger containers to insulate roots;
- Place pots on the ground, group them, and cover with fabric or tarp.
- Alternatively, store pots in a garage after leaf drop. Light is not required. Check moisture occasionally.
Best Practices to Help Trees Survive Winter
Do
Water regularly in fall if conditions are dry, especially for conifers in their first years. Well-hydrated plants better resist winter desiccation.
Don’t
Avoid fertilizing or pruning between mid-August and early October, as this promotes new growth that won’t harden before winter.
Use Microclimates
Take advantage of sheltered areas or spots where snow accumulates. These natural microclimates offer additional protection.
Use these areas for less hardy plants.
While some species are becoming more adaptable, winter conditions can still be harsh. With proper protection, you can safely diversify your landscape and support biodiversity.
Article co-written by Suzanne Simard, horticultural writer and horticultural technologist, and Audrey Rondeau, Biol., M. Env., Production and Development Director at Pépinière Vert Forêt.
References
Protecting container-grown shrubs in winter (n.d.) Du jardin dans ma vie. Accessed october 23 2024, at the following address: https://dujardindansmavie.com/conseils-idees/arbustes-fruitiers-en-pot-comment-les-proteger-pour-lhiver/
How do trees survive winter? -Parlons sciences. (n.d.). Accessed October 1, 2024, at the following address: https://letstalkscience.ca/educational-resources/stem-explained/how-do-trees-survive-in-winter
Winter protection for trees and shrubs. (n.d.). Espace pour la vie. Accessed October 1, 2024, at the following address: https://espacepourlavie.ca/protection-hivernale-des-arbres-et-des-arbustes
Header image by wirestock on Freepik
