Warmer summers could mean new plants growing in Manitoba, says horticulturalist

Manitoba's potential for longer and warmer growing seasons, coupled with wild weather changes, could change how people approach gardening in the province, experts say.

While it's hard to predict whether the province will start to see a longer or earlier growing season, plant types and growing patterns are changing in tandem with the climate, says Sajjad Rao,a horticulture research instructor at Brandon's Assiniboine Community College.

"We're shifting," he said, and the time to start adapting is now.

"The changes coming from the climate is compelling us to do that, because then we have to come to a resilient agriculture, or a resilient horticulture."

Most of southern Manitoba is designated a cold-climate Zone 3 plant hardiness zone — but there are spots where Zone 4 plants, which thrive in warmer environments, can now be grown, Rao said.

Globally, last summer was one of the hottest on record. This past December, January and February were the warmest on record in Canada in 2024.

Manitoba has also seen swings from drought to flooding in recent years. In 2022, several climate experts told CBC that may be a sign of things to come — and a reminder that people need to be prepared for more extreme weather in the future.

In Brandon, gardeners are trying to adapt to these changes in weather and climate. 

While spring planting typically still starts around the May long weekend, gardeners are changing how they maintain plants in the summer. That includes steps like increasing mulch usage, said Brian Fowell, a co-ordinator with Brandon's Hummingbird Community Garden.

"During the summer we do get hotter, which … make[s] such a difference with our water we have here," he said.

"But if you water, put some mulch down, you can keep that water — because if not, everything wilts out in the heat."

Other changes include trying to grow new types of vegetables, along with long-time staples like carrots and squashes, he said.

Changes to Manitoba's climate are gradual, but they start to add up, Rao said.

He cited frost-free days in Brandon as an example — typically, the area gets about 105, and at most about 117 in a year. But by 2050, that number is expected to grow by at least 30 days, based on data and research, Rao said.