Plant science Winter Protection

Gardeners Should Be Hoping for Lots of Snow…and Soon!

Larry Hodgson has published thousands of articles and 65 books over the course of his career, in both French and English. His son, Mathieu, has made it his mission to make his father’s writings available to the public. This article was originally published in the newspaper Le soleil on November 21, 1992.

In mid-January, when it’s so cold that it hurts to even breathe, it’s hard to believe that plant life can survive a climate as harsh as ours. But the proof is in the pudding: many plants do just fine. Here’s how.

Garden under the snow
A garden under the snow. Photo: Yann, Wikimedia Commons.

Different Reactions

Each plant has its own way of resisting the cold. Some, for example, react… by dying! This is the case with so-called annuals: the adult plant dies, but not without having produced seeds that are often very resistant to the cold. When the warm sun returns in the spring, the seeds, which were previously in a deep sleep, germinate and quickly produce an adult plant which, in turn, will produce seeds, and the cycle continues.

Another way for plants to resist the cold is to let their aerial parts die, but not their crowns (growing point) or their roots. Under the ground, especially if there is a thick layer of snow, the temperature barely drops below freezing (and it is easier to survive at 25°F (-3°C) than at -25°F (-30°C). Perennials react this way, and so bulbous plants.

Tree that has lost its leaves
Deciduous plants shed their leaves to conserve water. Photo: PxHere.

Woody Plants

Woody plants (trees, shrubs and vines) don’t have it so easy. Their aerial parts remain exposed to the cold wind throughout the winter. To survive, they will have to go through a gradual acclimatization period. As the nights get colder, different physical and chemical reactions occur to prepare the plant for the cold to come. Each species has developed different techniques to protect itself from the cold during its evolution.

Deciduous plants, for example, lose their leaves. Exposing the large surface area of their leaves to cold winds would cause too much water loss. Conifers, on the other hand, keep their leaves because they are in the form of thin needles (very small surface area) covered with a thick cuticle that reduces water evaporation.

Plants also reduce the amount of water in their tissues as a result of increased cold. The cells of a well-watered bud would burst in the cold, but if they are almost dry at the time of freezing, the damage is limited.

There are also various chemical reactions, often still poorly understood, that protect plants from the cold. It’s as if the plant produces its own antifreeze.

Forest in the car
A warm late fall will often cause more damage to plants than a cool fall. Photo: Larisa Koshkina.

Variable Resistance

The cold hardiness of most plants is only valid if the plant has time to prepare for it. Normally, the mild, cooler days of fall bring a gradual increase in cold hardiness. Thus, even a very cold-resistant plant like spruce would be severely damaged by even a light frost in midsummer, whereas it would have easily survived a -30°F (-35°C) frost in mid-winter. Thus, an abnormally warm late autumn will often cause greater damage to plants than a chilly autumn: in the first case, the plants won’t have had time to harden to the cold and when the Siberian temperatures arrive overnight, they won’t yet be ready to face them.

Snow on pots
Since a container is more exposed to cold than the garden soil, roots would experience a deeper freeze and could die. Photo: Crisalex37, Wikimedia Commons.

Uneven Resistance

The same plant can have different levels of cold hardiness. The buds that produce the leaves, for example, are often more resistant than the flower buds. This explains why some plants, such as forsythia and rhododendron, survive a particularly cold winter well but do not flower the following spring. In addition, the roots of plants are usually less resistant to the cold than the aerial parts. This is why a perennial that is very resistant to the cold may not survive the winter if it is grown in a flower box. Because the container is more exposed to the cold than the garden itself, the roots would freeze more deeply and could die.

House buried by snow
The best natural protection for plants is a good snow cover. Photo:

The Best Protection

The best natural protection for plants is a good snow cover. Generally speaking, the earlier and more abundant the snow falls, and the later it stays in the spring, the more beautiful our gardens will be. This is why gardens in eastern Quebec are generally more attractive in the spring than those in the warmer Montreal area.

So, gardeners, let’s hope for lots of snow, and as soon as possible!

Garden writer and blogger, author of 65 gardening books, lecturer and communicator, the Laidback Gardener, Larry Hodgson, passed away in October 2022. Known for his great generosity, his thoroughness and his sense of humor, he reached several generations of amateur and professional gardeners over his 40-year career. Thanks to his son, Mathieu Hodgson, and a team of contributors, will continue its mission of demystifying gardening and making it more accessible to all.

4 comments on “Gardeners Should Be Hoping for Lots of Snow…and Soon!

  1. An outstand?ng share! I have just forwarded this onto a friend who ?as conducting a little research on this. I used to b? checking continuously this website and I’m inspired! I used to be seeking this particular info for a very lengthy time. I am linking to this great post on my site: Thanks and good luck.

  2. Snow has not happened here since 1976! It was a major problem back then, and it would be even worse now, with so many more people living here, and so many who do not know what to do with snow. Redwoods that have never experienced it are very sensitive to snow. Their limbs break from the weight. However, we rely on snow to store water in the Sierra Nevada.

  3. Well I guess our wish has been answered as we have had two heavy snow falls already. Unfortunately, the plants were still going strong before they were buried so will be interesting to see how they coped come Spring.

  4. Jt Michaels

    “The cold hardiness of most plants is only valid if the plant has time to prepare for it.”

    A perfect example of Mr. Hodgson’s brilliant understanding!

    He’d be pleased to know those of us in Northern MI have several feet of an insulating snow layer (but poor Buffalo!).

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