Just before our latest Extreme Cold Warning came into effect, we also ended up with a snowfall warning. Not only were temperatures about to plummet, but we were going to get a good dump of snow on the way down.
For all the winter-haters out there, this seemed like the worst case scenario. As a gardener and orchardist, I was actually relieved to see the snowfall warning before the deep freeze.
The shoveling isn’t always fun, and the icy roads and sidewalks can be challenging – but would a winter without snow really be a good thing? There are actually reasons to love the snow, it helps cover some of the dull brown of the colder months, helps provide a ready source of moisture in the spring, and helps insulate plants from cold weather.
The insulation that snow provides is the reason a snowfall warning before a cold snap is actually good news to me. A reliable snow cover provides a nice blanket over the ground. While the soil will still be cold, underground temperatures will be protected from the deepest cold of a cold snap. For perennial plants this is important, because the roots are typically more sensitive to cold temperatures.
Using Snow Strategically
Once you realize that snow can actually be a blanket you can use this to your advantage. Whenever I need to shovel, I do my best to intentionally toss the snow towards my trees and perennial plants. When I know really cold temperatures are coming, I’ll even go out and spend some time specifically burying the most tender plants and trees in as much snow as I can. When the temperatures get as low as they have this year, I know that some of my marginally hardy plants are being pushed right to their limit. A little bit of extra insulation might mean difference between a dead tree and a live tree, or at least reduce any winterkill.
How Much Snow?
To get the benefits of snow for our plants, we need to get enough of it, and we need it at the right times. People often perceive the prairies as particularly cold and snowy in the winter. But as it turns out, we actually are less snowy than many other parts of Canada.
Here is the average annual snowfall in some Canadian cities in order of increasing annual average snowfall*:
- Saskatoon-90 cm
- Regina- 100 cm
- Winnipeg -110 cm
- Toronto – 110 cm
- Edmonton-120 cm
- Calgary -130 cm
- Montreal – 210 cm
- Ottawa -220 cm
- Quebec – 300 cm
Snow at the Right Time
This may sound like a lot, but remember that some of the snow falls early in the season and then melts during the warmer winter days. Some snow falls late in the season, after the coldest nights. We don’t usually have 100 cm of snow on the ground all at once. Our snow cover during the winter will usually only be a fraction of the total annual snowfall. Because our winters aren’t actually incredibly snowy, it is important that snow we do get comes at the right times. Ideally, the best scenario is deep and consistent snow cover during the coldest part of the year.
Luckily for most of us, the weather usually does cooperate. For most of the Prairie cities, the months that typically have the highest snowfall are December and January*. This is pretty handy because it helps ensure there is usually a nice blanket over the ground when the coldest weather hits. If the snow tended to hold out until February – any cold snaps in December or January would be extra hard on the plants. There is an exception though – in Calgary, where the snowiest month is actually right at the end of the season in March.
But How Much Snow is Actually on the Ground?
All of the prairie cities reach their maximum snow depth in January or February*. This suggests we tend to get a decent amount of snow early enough in the winter to cover everything up. Enough of that snow also tends to stick around to help protect plants during the coldest part of the year. Calgary, again is an exception here, as southern Alberta is more prone to winter thaws that reduce the snow cover. In January-Feb you are likely to have around 14-20 cm of snow on the ground in most of the prairies, but in and around Calgary, that number drops to 4 cm.
Calgary isn’t the only exception to understanding prairie climate. Winter across the prairies is not as uniform as it sometime seems. We’ll delve a bit more into these differences in the next post.
For now, maybe next time you see a big snowfall forecast, especially before some really cold temperatures – just remember that the snow is actually doing some good. It is helping protect all of the greenery that you are looking forward to in the Spring. It’s also just beautiful and in our opinion, makes winter way more fun!
* Note - All climate data is taken from Environment Canada historical Climate Normals 1981-2010 at each cities' International Airport.