Okanagan Valley winemakers and executives say they are enjoying the best growing season in years even though the risk is always present that a severe heat dome could ravage crops.
After all, the industry has been rocked by extreme cold snaps in the past few years, and climate change can exact its wrath in unpredictable ways.
This is why researchers are exploring how heat can stress grapevines, and whether winemakers can use soil additives to improve vineyard yields.
Hester Creek winery president Mark Sheridan told BIV that the growing season since April has been one of the warmer ones he has seen since he moved to Canada from Australia in 1999, and that this is preferable to having a cooler start to the year.
“The earlier the better for heat,” he said. “This season has been very good in terms of heat units.”
Sheridan’s winery saw about 25 per cent of its vines killed last year by the January 2024 deep freeze, which included temperatures plunging below -20 C.
That meant his staff had to replant those vines earlier this year. Vines that survived the harsh winter are thriving, he said.
Others in the industry have done what Culmina Family Estate Winery assistant winemaker Caroline Schaller calls “retrunking.” That is when staff replace vine trunks without having to replace entire vines.
“So far, everything is doing very well,” she told BIV. “We are very happy with the vines this year.”
Warm weather has helped turn some of her Merlot grapes red earlier than she might have expected, she said.
“Summer can be very hot here,” she said. “We have had a couple of days now where we're reaching between 35 Celsius and 38 Celsius, which is pretty hot. So far, we haven't reached 40 Celsius.”
Schaller said she noticed a similar heat spike a few weeks ago but it only lasted a couple days.
Blasted Church winemaker Evan Saunders agreed, saying that his Okanagan Falls winery has not seen any long stretches of heat.
“The vines have bounced back better than I think anyone had hoped,” he said.
Over at Painted Rock Estate Winery, owner John Skinner described the summer as a “banner season,” which is being helped in part for his winery by the way he designed his vineyard so vine rows are in an east-west direction.
That means that the vines enjoy needed air movement up from nearby Skaha Lake. In winter, the vineyard alignment helps because if blistering cold blows down from nearby mountains, it can flow through pathways between vines and not smack them head-on and kill them.
Skinner said this helped him escape the cold snaps in December 2022 and in January 2024 without any vine death. He only suffered some bud-loss last year.
“When it gets above, around 38 Celsius, the plant just kind of shuts down,” Skinner told BIV. “It's not a big negative, but you're just not progressing.”
This year’s crop is poised to be a bumper one, on par with other great vintages, such as in 2022, he added.
BC Grape Growers’ Association CEO Jeff Guignard told BIV that he has heard other winemakers similarly say that they expect this year to be their best harvests since 2022.
“We had two really, really rough years,” Guignard said. “That's part of the enthusiasm out there. It’s like, finally, we’re getting some really beautiful fruit. Years from now we will look back at 2025 as being an incredible vintage.”
What is even better is that visitors are returning.
“It has been a busier tourism season, which is incredibly helpful for all of the tasting rooms, restaurants and hotels,” Saunders said.
Research on how heat stresses grapevines is underway
Despite this summer’s great weather, the risk that a severe heat dome will materialize looms and is spurring research.
Genome BC-funded researchers are using genomic techniques to learn how heat stresses grapevines and what the industry can do to minimize negative effects.
The work is a partnership between non-profit Genome BC, the University of British Columbia’s Wine Research Centre, the Canadian Grapevine Certification Network, the BC Wine Grape Council and Andrew Peller Ltd.
The team is also studying how so-called “biostimulants” impact plant defences. These are substances such as certain types of acids, seaweed and plant extracts, beneficial bacteria, fungi and microbes that researchers put on plants or soil to help them grow and absorb nutrients while helping the vines tolerate stress.
"We need to know more about how they actually work," said lead researcher Simone Castellarin, from UBC's Wine Research Centre, about the biostimulants.
He said he hopes the study will lead to more clarity on how much of soil additives to use and how to apply them.
Researchers are also measuring plant leaves and berries at various times to understand how they react physiologically and metabolically to heat stress.
"Crop loss isn't just a problem for winemakers and growers,” said Federica Di Palma, Genome BC's chief scientific officer and vice-president of research and innovations.
“This ultimately affects the quality and reputation of B.C.'s wine industry. Here, we clearly see the value of genomics not just to agriculture, but also to our economy."
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