“In Ontario, we have a similar case with some regions and areas having significant damage (Southwest Ontario) but in Niagara, the largest production area, the amount of injury is highly variable,” Brock University Professor Kevin Ker told Wine-Searcher.

Ker, a grape and wine industry consultant, who lists vine winter hardiness as one of his areas of research, said that, while the field examinations would not be completed until the end of June, he expected yields for the 2014 harvest would be down 50-75 percent compared to the average crop, with some growers having even less depending on site and cultivars grown.

Paul Pender is a winemaker for Tawse Winery near Hamilton, Ontario. Its vineyards sprawl across the neck of land that separates two Great Lakes – Erie and Ontario. “There’s no Merlot. No crop at all. That’s the worst hit for us,” he said.

“I’m quite pleased with the Cabernet Franc, the Pinot Noir and the Riesling. I think we’re only going to be down about 35 percent of our buds,” Pender added. “We’re not looking at a total disaster. I don’t think we got hit as bad as the Finger Lakes.”

His remarks echoed those of Debbie Zimmerman, head of the Grape Growers of Ontario, an organization that represents more than 500 growers in the region. She explained that the situation was not as dire as Finger Lakes. “Due to our technology and pruning practices, we are doing okay to date.”

At Constellation Brands’ Inniskillin, Keith Brown, vice president of winemaking and viticulture, said that growers weren’t out of the woods quite yet.

“Other risks beyond spring frost, include late spring start (which we are seeing), poor set due to rain at that time of year, poor ripening due to lack of growing sunshine hours, fall frosts, high disease pressure, pest problems including birds and, lastly, rain-days during harvest," he said. "But apart from that all is golden in the vineyard.”