Gardening expert Jim Hole watches green-thumb keeners troll for seeds in the dead of winter.

And why not? Due to climate change, Edmonton gardeners have more choice than ever.

Jim Hole

Gardening expert Jim Hole gives advice on what to plant and when at The Enjoy Centre in St. Albert. (John Robertson/CBC)

"We're not getting as many severe cold winters so it is a major boom for people who want to try more things," Hole said. 

"We used to be a Zone 3A. Now we've moved up to a Zone 4A. Because of that there are more things that we can grow." 

The owner of The Enjoy Centre in St. Albert has seen sugar maples, Japanese maples, different varieties of pears, apples, even corn, thrive.

"Now you'd be hard pressed not to find a year — if you plant at the proper time — we don't get a really good corn harvest," said Hole.

Edmonton is just one of 374 communities in Alberta that have seen their growing zones change, according to Dan McKenney, senior scientist with Natural Resources Canada based in Sault Ste. Marie, Ont., and an author of Canada's new plant hardiness zone designations published in 2015.

spring planting

Gardening experts suggest you check the zone rating on the back of seed packages before you plant. (John Robertson/CBC)

The federal agency uses a formula established in the 1960s to factor in wind speed, weather station data, precipitation, minimum temperature of the coldest month to designate zones. 

plant hardiness zone

A map of the updated plant-hardiness zone for the Alberta. (Natural Resources Canada)

"Time has passed, climate is evolving. All we did is just basically applied the same formula and that's what's caused the changes," McKenney said. 

What it boils down to growers is more choice.

"That's pretty significant for gardeners. They all like to push the envelope in trying to plant things that are on the edge of the survival ratings for their particular place," said McKenney.

Aaron Webb, assistant grower at Arch Greenhouse, gets questions about growing zones all the time.

"Right now people are eager. There's a general excitement for the upcoming season," he said.

But Webb believes gardeners should temper that spring fever enthusiasm with the knowledge these zones are just guidelines.

"It just means these plants have a greater chance of surviving," said Webb.

And gardening is far from an exact science. 

plants

Garden centres across Alberta are getting ready for the onslaught of eager gardeners. (John Robertson/CBC)