Lighting up the vines with Frolight’s infrared system may be the cold snap solution wineries are looking for.
Climate change-fighting innovations like infrared lighting, sprays and fabric strike back at cold-weather challenges
A string of lights might help save B.C.’s grapevines from another fatal cold snap.
Belgian company Frolight’s vine-warming system made a good impression at a trial run with Quails’ Gate Estate Winery this past winter in their vineyards on the East Kelowna Slopes.
Winemaker Rowan Stewart is pleased with the results. After consecutive deep freezes two years in a row destroyed about 200 acres of grapes, the winery began testing new methods to prevent future winter damage.
One deep freeze is expected, says Stewart. But, two in a row is difficult to take. “We lost a hundred acres the year before and then we lost another hundred acres [in early 2024] so we’re replanting over 200 acres,” he says.
Light it up
The Frolight system was strung along four rows of grapes with lights set to deliver heat directly to vine buds by gently warming the plant.
“The infrared goes into the vegetal tissue,” says Noël Fourcroy of Oak Leaf Inc., the Quebec-based distributor of Frolight for Canada.
Frolight was designed and proven to address spring frosts, but facing the middle of a Canadian winter was a bigger challenge.
“It seemed to work pretty well,” says Stewart. “About four degrees [Celsius improvement] was the consistent result. There were some areas where it was a bit better.”
Although the 2024-25 winter seemed comparatively mild, Stewart says a cold snap in early February, where temperatures plunged to –17°C, put the system to the test.
“We did the evaluation with that cold snap we had… that’s where we really got all of our numbers,” says Stewart. “My main worry was, would it even do anything at negative 20°C?
“We got negative 17°C, and it seemed to be working fine.”
Three Canadian vineyards tested the system during the winter and several more used it for spring frost protection. Frolight is used by about 600 vineyards worldwide, Fourcroy says.
“The big advantage of this system is it protects from the black frost,” he says.
Black frost happens with a sudden temperature drop. You can’t see it, unlike most frosts, but it turns plants black.
While Okanagan winters are generally warmer thanks to climate change, that also brings new dangers.
“It’s not always as cold as it was before, so the big problem is in warm winters, which are more and more frequent everywhere, when a vortex shows up the plant doesn’t have the time for adaptation,” he says, noting Nova Scotia, Ontario and B.C. have all been hit by sudden freezes.
The 2023-24 Okanagan winter saw thermometers plunge amid mild temperatures. With no snow cover, vines and tree fruits suffered widespread damage.
An expensive necessity
While a few temperature-triggering adjustments might be needed, Stewart hopes to expand use of the Frolight system next year but it isn’t cheap — at up to $20,000 an acre.
“All the systems against cold are pretty expensive,” says Fourcroy.
Quails’ Gate has also been trying other systems. Stewart says it’s too risky to do nothing, especially in more marginal vineyards.
“If you want to be planting new sites, you absolutely have to have a solution,” he says.
“Our best sites around the winery, they didn’t need protection. They survived but they lost their whole crop so there’s a lot of recovery work to do, but they’ll still be around the next couple of years. The other sites that we’re planting that were further afield and are marginal sites, a lot of them went down and will need protection.”
The winery is considering adding protection for 10 acres next year.
While $20,000 an acre sounds like a lot, the investment in Frolight pays for itself, says Fourcroy.
“If you have a system that can guarantee you a production of 80 to 100 percent of your buds and help you guarantee that every year, and avoiding damage to your plant, then I think the price can be considered to be not that heavy.”
Vahid Ikani, an agricultural meteorologist at the Université de Sherbrooke, tested Frolight in a Quebec vineyard. He says generally methods such as wind turbines, SIS [an air movement system] and irrigation struggle to increase air temperature once it drops to -6°C or -7°C.
“We recorded that the Frolight cable increased air temperature by nearly two degrees at -12°C,” he says. “This finding highlights the potential of the Frolight cable not only for spring frost protection but also for applications in winter conditions.”
The system distributes heat evenly and targets the spots that need it, which other systems don’t, he adds.
Frolight requires precise setup, says Ikani, but is easy to operate. “How we attach it to the branch is ultra important. It is very user-friendly.”
Essentially, roll out the wires and line them up in the fall, then roll them back in the spring. It’s less labour-intensive than other similar systems.
We recorded that the Frolight cable increased air temperature by nearly two degrees at -12°C. This finding highlights the potential of the Frolight cable not only for spring frost protection but also for applications in winter conditions.”
— Vahid Ikani, agricultural meteorologist, Université de Sherbrooke
Wind machines and warm covers
Wind machines look promising, says Stewart. They work well against frost, but aren’t proven in the dead of winter.
Popular in Washington state, they pull down warm air, but don’t work when it’s too windy. And sometimes there isn’t any warm air to pull in, Fourcroy says.
In February, South Okanagan grower Gagan Dhaliwal told the Southern Interior Horticultural Show in Penticton about his family’s success at Fairview Hill Vineyard with new app-controlled wind machines.
“Prior to this, we were doing it very practical, standing outside in the minus weather looking at the temperature and firing up the wind machines then. For us it doesn’t really make sense once you’re looking at 15 to 16, 17 different wind machines and they all need to be turned on around the same time. So Altrac [the app] definitely made our lives easier,” he says.
Geotextile is another method Stewart is trying. “It’s a fabric that they roll out on top of the vines. It creates a pocket of warm air,” he explains.
But it’s expensive and labour-intensive to set up. “Talking with a guy in Quebec, it’s their single largest expense in the vineyard,” says Stewart.
Promising spray solutions
The Penticton conference heard that spraying may be another option, as three panellists described new sprays they hope will soon be ready.
“We’ve had as high as six degrees [Celsius] improved hardiness. Can we get to minus 35°C or minus 30°C? I’m not certain,” says Jerome Konecsni, CEO of Saskatoon-based ABAzyne Bioscience.
ABAzyne hopes to have ABA Boost approved for use by the end of 2026. Their spray, designed specifically for wine grapes, is applied post-harvest, puts plants into dormancy quicker and delays budding in the spring, but does not affect timing of the maturation process.
“It improves the cold hardiness of the buds and it extends dormancy therefore delaying bud break,” he says. “It’s lowering crop losses as a result of these cold and frost events.”
“Freak frosts” which happen in late spring after plants have started budding, have become the new normal, says Collin Juurakko, a research scientist with B.C.-based Advanced Agriscience.
“We’re consistently seeing these kinds of events increase in frequency and severity around the world,” he says.
His company is developing a shelf-stable biological spray that uses microbes to work at the molecular level. Applied before a forecasted frost, it enters plant tissue and stops ice-crystal growth.
“We are directly treating the cause of frost, the molecular cause, as opposed to treating the symptoms,” Juurakko says.
The cost will be about $5 to $20 per acre with protection to -8°C for two weeks, he says.
The company plans field tests soon.
ABA boost improves the cold hardiness of the buds and it extends dormancy therefore delaying bud break.”
— Jerome Konecsni, CEO, ABAzyne Bioscience
Sappi, an American forestry company, hopes to bring a spray developed at Washington State University to market soon, shared Matthew Whiting, a tree fruit horticulture professor.
The spray provides a protective coating for cherries, apples and other fruits. Large-scale trials have shown reduced mortality and increased yield.
“I expect it to be commercially available by this time next year,” the Canadian researcher says.