What Does a Mild January Mean for Our Plants?

It’s not the first time we’ve had a mild January in the region. I remember planting tulip and narcissus bulbs in January when all the snow was almost gone and the ground had thawed. That was about twenty years ago. But in the 30-plus years I’ve lived in the Quebec City, there’s never been such a long-lasting thaw. What does such a mild January portend for our gardens and plantations?

So far, so good! Did you really think that plants need -20°C (-4°F) to be happy? Many tolerate it, but none require it. Right now, the temperature is hovering around 0°C (32°F): a little more, a little less. Still, it’s winter rather than spring: nothing that will stimulate most plants to start growing.

Photo : Roy Post

A Few Exceptions

But there are exceptions. A little more of this temperature and small bulbs like snowdrops (Galanthus nivalis) and eranthus (Eranthis hyemalis) will wake up, and maybe even crocuses and early perennials like hellebores. What will happen to them if they’re in full growth and winter suddenly comes back with a vengeance?

Nothing, or very little. Their flowers will probably remain frozen in the snow, which won’t be long in coming if the temperature drops, and their blooming will continue when the snow melts in true springtime. The worst thing would be if it were very cold and there was no snow. In that case, flowers and leaves could freeze and die. But nature has provided plants with reserves for just this sort of thing: they’ll quickly regrow their leaves. Flowers, on the other hand, won’t get a second chance: they’re finished for the year. They won’t be seen again until the following spring.

No, they’re not. They’re just as happy as you and I are about the warm weather. If winter stays mild until the end, they should respond enthusiastically in spring, with prodigious growth. Cold winters slow growth, mild winters stimulate it.

The Plants Most at Risk Are Those Outside Their Zone

Curiously, the plants most at risk at the moment are those that are outside their normal zone; the little zone 5 perennial you planted in zone 4, for example. And there are bound to be plants that were considered to be such and such a zone, because they had responded well up to now, but won’t respond as well without snow cover… we may learn that they’re less hardy than we thought. These plants risk being eliminated from the map. From a laidback gardener’s point of view, this is a good thing. The weak will be eliminated, the strong will grow better than ever. What more could you ask for?

Dried buds on a rhododendron.

The Situation Among Horticultural Professionals

Don’t worry about nursery owners. Their hardy plants are well bedded down and covered with canvas or tunnels. A mild January means fewer losses.

As for greenhouse growers, they’re greasy: heating costs haven’t been this low in ages!

What Will Spring Bring?

If there’s one risk for gardeners following a mild winter, it’s not so much the mild weather as the risk of a dry spring. Usually, our springs arrive late, as the snow doesn’t finish melting. But by melting slowly, it maintains good water reserves in the soil. That’s why we so rarely have real droughts in our region. If there’s no snow, however, the soil can warm up earlier, stimulating earlier growth that quickly uses up the water in the soil. If our spring arrives 2 months early, but is not accompanied by rain, there could be a drought this spring or summer.

Photo: PhotoMIX Company 

But all this is in the conditional tense: “if there’s no snow this winter”. Winter’s not over yet, and we’re likely to see all kinds of temperatures again, including snow and cold.

For the time being, our plants are enjoying the unusually mild weather. We’ll see what happens later!

Larry Hodgson 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 accessible to the public. This text was originally published in Le Soleil newspaper on January 13, 2007.

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.

3 comments on “What Does a Mild January Mean for Our Plants?

  1. nancy koch

    Rose bushes coming out of dormancy is what i am worried about

  2. It is not so much the warm temperatures but the extreme oscillation from very cold to very warm that are concerning this year.

  3. Aside from one cold snap, we are having a very mild winter so far in northern Ontario, zone 2b.

Leave a Reply

Sign up for the Laidback Gardener blog and receive articles in your inbox every morning!