Sweet Potatoes in Canada?

By Matt McIntosh

New variety of sweet potato designed to grow in shorter spring and summer seasons.

All farmers face challenges from Mother Nature. In some parts of the world, overly dry or rainy seasons pose a challenge – but in Canada, it’s the cold.

Different crops require different lengths of time to grow and mature. Even in Canada’s most southern regions, there are many crops – those grown in greenhouses excluded – which struggle to mature before the onset of the cold weather for which our country is so well known.

It’s a challenge that can be at least partially addressed by developing crop varieties specifically for the Canadian climate.

As of a few years ago, the sweet potato became one such crop.

American varieties bring challenges

There are about 2,000 acres of sweet potatoes grown in Ontario each year, plus a handful of additional acres in Nova Scotia. Sweet potatoes are grown by planting “slips,” which are vegetative cuttings of other sweet potatoes, and Canadian growers have to import these from the United States.

However, the varieties being grown in the United States – specifically in North Carolina – are better suited for a longer growing season. This puts additional pressure on growers on this side of the border to get the crop planted and harvested as quickly as possible.

After placing slip orders, Canadian growers also must send trucks to pick up the order. This incurs significant transportation expenses, as well as potential importation complications at the border. But with no domestic propagation to speak of — at least, not on a scale large enough to supply Canadian growers — no alternative solution currently exists. The sheer distance from North Carolina propagators to potential growers elsewhere in Canada is also a barrier in itself.

A made-in-Canada variety

Plant breeders at the Vineland Research and Innovation Centre in Ontario tried to address these challenges by developing their own variety designed to be propagated and grown in Canada.

Released to growers in 2019, the “Radiance” sweet potato variety matures 11 to 20 days sooner than its American counterparts. This might not sound like much, but even a few extra days can make a huge difference when it comes to harvesting crops.

During its development, researchers also discovered it yielded a greater quantity of the edible root, and could be planted closer together without adversely affecting the amount of crop produced.

Getting it to growers

Canadian greenhouse growers could also get involved. As with other crops, greenhouses provide a climactically-reliable environment with lower exposure to the viruses and pests which can hurt sweet potato slips. The level of greenhouse technology does not have to be top-tier either, so greenhouses otherwise too outdated to efficiently grow other crops could be used. The combination of closer suppliers and an earlier maturing variety would mean sweet potato growers could save a lot of time, money and associated headaches. 

Things take time, though. Indeed, slip propagation takes several years to ramp-up before the supply reaches a point where they can be sold to growers.

The Radiance variety is still quite new. A lack of propagators has been cited as the main barrier to getting the variety to Canadian growers. But it is attracting interest both in Canada, and in other parts of the world where winter takes a larger share of the seasonal pie.