Winter deep freeze takes its toll on Ontario vineyards

by MATT MCINTOSH

January’s sub-zero weather has taken a toll on Ontario’s vineyards, with frigid temperatures and high winds killing off significant portions of certain grape crops.

“The temperature here dropped to -23 C for a couple days early in January, during what people were calling the polar vortex,” says Harvey Hollingshead, one of the owners of Erie Shores Vineyard in Essex County. “The extreme cold plus high winds meant we had almost 80 per cent bud kill on our vinifera grapes.”

Rick Lakeit, owner and grower at Niagara’s Caroline Cellars winery, says some of their grapes have also taken quite a bit damage, with bud loss ranging between five and 75 per cent.

“We have damage on all our plants,” says Lakeit. “Our hybrid varieties were damaged the least, and the vinifera grapes were hit the most; particularly merlot, which had 50 to 75 per cent bud kill.”

Ontario vineyards grow two different strains of grapes; hybrids, such as the vidal, and vinifera varieties, such as merlot and chardonnay. While hybrids are more adept at withstanding colder temperatures, vinifera grapes – or purer European varieties – are more susceptible to frost and damage from freezing.

According to data compiled by researchers from Brock University and KCMS Applied Research Consulting Inc., an agricultural consulting firm, primary bud survival rates for vinifera cultivars vary widely.

In the Lake Erie north shore region, for instance, only about five to ten per cent of all primary chardonnay buds survived January’s first winter blast. Conversely, anywhere from 80 to 93 per cent of primary chardonnay buds survived in the region of east Niagara. Other cultivars like merlot follow a similar pattern, with a zero to 25 per cent bud survival rate in Lake Erie’s north shore, and a 30 to 51 per cent survival rate in Niagara west.

“There can be quite a range in survival depending on location, last year’s crop load, and overall viticultural practices,” says Ryan Brewster, field services manager at KCMS Applied Research Consulting Inc. “There are secondary and tertiary buds that will compensate if the primary bud is damaged, but they are typically much smaller in size and very little crop is present.”

For vineyards in Prince Edward County, Brewster says he and the other researchers are not expecting any buds to be alive.

Growers there, he says, will be relying on buried canes for the upcoming season.

Debbie Zimmerman, CEO of Grape Growers of Ontario, says that growing traditional varieties of grapes in Ontario can be difficult, but there are ways growers can improve their success rate. Fans, primarily, are used to redirect warmer air downwards, sparing the vines from frost and extended periods of exposure to frigid air.

“The problem our growers experienced this time was that the air was too cold, and the wind was too high,” she says. “Fans can’t do anything if there is a lot of wind.”

Zimmerman says many growers will, undoubtedly, be using their crop insurance this year. BF