Cold Snap Brings Widespread Bud Damage

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Wine grape growers in the Okanagan Valley could face a disastrous harvest this year, due to a brutal cold snap over Christmas.

Miles Prodan, CEO of the Winegrowers of BC, says the decline in crop yield is potentially disastrous.

“It looks dire,” Prodan said. “It looks like it could be anywhere between 30 to 40 per cent, maybe even higher, but more importantly, compared to previous years, it looks as though it’s not necessarily as isolated as it has been, it looks like it’s all up and down the valley.”

Research Finds Up To 100% Of Buds Damaged In Some Areas

The Summerland Research and Development Centre unveiled results from a recent bud dissection showing widespread bud damage across the Okanagan Valley. In some areas, the research centre said 100% of the buds they checked showed primary and secondary bud damage, including the Central Okanagan and the Oliver region.

Even worse, many areas are also seeing damage to the trunk as well, which will often negatively impact the yield for wine grapes over a period of multiple years, not just a single harvest.

Research scientist Ben-Min Chang says he first saw the bud damage in a planting of wine grapes operated as a research plot by the Summerland research centre.

“We had a pretty bad cold snap starting December 22nd,” explained Chang. “Before that cold event there was approximately 10 per cent of the buds that were damaged, but after the event I saw 70 per cent at least in our experimental vineyard.”

The numbers were alarming enough that Chang decided to start checking buds in other areas of the Okanagan Valley, and in some of those growing regions the results were even worse.

“Overall the Kelowna area looks pretty bad,” said Chang. “Most of the wine grape damage was around 100 per cent, except for the hybrid varieties, which were around 50 per cent.

“Down south it looks slightly better,” Chang added. “Some places like Naramata Bench are doing okay, as their damage rates are very low, like around 10 per cent, but in other places, like Oliver, I was actually very surprised … I also saw severe damage there, sometimes 100 per cent damage.”

Chang also noted that the damage was very patchy, as one vineyard might show only 70 per cent damage, and another vineyard next to it might see 100 per cent damage. That variation in damage rates is not surprising, as frost damage can be worse in flat fields where one encounters frost pockets, and there are also various ways that growers can mitigate frost damage.

However, based on what he’s seen so far, Chang says, “The overall yields in 2023 are not going to be very good.”

Still, there are factors that could improve the result over time, and Chang notes that just because there is 100 per cent bud damage in a specific vineyard, does not mean scientists can predict accurately how bad the decline in yield will be.

For example, Chang noted that some varietals like Riesling have an ability to recover from frost-related bud damage, and growers in the Okanagan with their experience in cold weather growing are skilled in minimizing damage from weather extremes.

A more serious issue, he said, is the potential for long-term declines in grape yields due to trunk damage.

Researchers Also Discovered Trunk Damage To Vines

“We talked about bud damage but I am also seeing some trunk damage,” Chang explained. “That’s another big concern. Trunk damage means the cold penetrates through the trunk and kills off those vascular tissues, and once the vascular tissues are dead the vine cannot receive water or nutrition, so at a certain level the grower has to decide to renew that vineyard. That would guarantee at least two years of really, really low crop yields.”

Unfortunately, the Summerland research station is not in a position to say how widespread the trunk damage is. Chang says checking for trunk damage is extremely invasive and involves cutting into the trunk, which of course will severely damage the vine.

For that reason, it is typically not possible to get an accurate reading on trunk damage until growers start seeing their vines starting to wither away.

“It’s hard to say how bad it’s going to be, but I would not be surprised at all to see a lot more replanting in the next couple of years,” Chang said.

Prodan also stressed that growers will not really know just how bad the situation is until the flowering period in late May or early June.

Wineries Looking At Severe Grape Shortage In 2023

However, the early indicators have growers concerned they won’t have enough grapes this year to break even.

“Our concern is if there’s not enough grapes, what do wineries do?,” Prodan said. “There’s the growers that need to know what are they going to do, because they can’t get paid for grapes they can’t grow.

“In addition to that is the question, what is a winery going to do if they don’t have grapes to process? We’re already starting to hear from some wineries that are concerned and starting to look at what can they do to be cutting costs.

“In an environment where costs are ever increasing, we’re seeing a perfect storm, setting up against wineries between costs increasing, and then the real possibility of having half as many grapes to work with as in previous years.”

Current Crop Crisis Part Of A Decade Long Decline

Another concern for growers is that the Okanagan has seen a general and long-term decline over the past decade, which most experts have blamed on extreme weather caused by global warming.

According to the BC Vineyard Resiliency Report issued in July 2022, crop yields have declined in BC by roughly 33 per cent between 2018 and 2022, with the tonnage decreasing from 30,000 tons to 20,000 tons over that period.

Most winemakers and viticulturists said that decline is due to a combination of climate change in general causing extreme weather events, and also the ‘knock-on effects’ of damage from recent weather anomalies like the heat dome, the flooding in 2021, and a damaging cold snap in the Thompson-Okanagan.

“Generally, we’re seeing some of the worst crops over a nine-year period,” said Prodan. “We’re very concerned about how climate change is affecting our grapes.”

The organization and researchers say steps are being taken to adapt to the changing climate and hopefully protect the wine industry.

“We may need to take a look at what we planted and where and then maybe take a look at replanting some of those grapes because they just aren’t able to survive where we are now,” said Prodan.

“I think there’s an opportunity to change over some of those grapevines. That’s going to take a huge investment by the industry and hopefully we can look and ask for some government support to help us with that as well.”

As reported in Orchard & Vine in November last year, grape yields did bounce back somewhat in 2022, after a truly horrendous year in 2021. That, of course, was when the harvest was impacted by the heat dome in June 2021 when temperatures soared to 44.6C, and 45C in Osoyoos.

However, if this year’s yield falls by anywhere from 30 to 50 per cent, that’s on top of the ongoing decline over the past decade, and would be an economic disaster for many wineries.

“Of course, we won’t know for sure what’s happening until flowering and fruit set, but it’s your planning, and you’ve got to be thinking of these things,” Prodan said. “They (wineries) know what they’re doing, and when they talk to the independent growers that they contract with, you know, they’re finding out everyone’s the same, so yeah, it doesn’t look good.”

Michael Kullman, winemaker at Osoyoos Larose, said the primary problem over the past decade has been the increase in unpredictable extreme weather events, including rain, heat and frost.

Kullman now has a theory that severe frost events at unseasonal times of the year is the single greatest culprit in the four-year decline.

“My theory is that with climate change we’ve been getting more and more frost each year … and that will cause lower yields,” Kullman said. “My gut feeling is that it’s the cumulative years of warmer winters and then more severe frost events in the spring, or like in early 2019 when we had the early autumn frost, is causing long-term damage to the vines.”

Chang and the team at the Summerland research station will continue their research this spring, and by late May or early June will be in a better position to predict how the December 22 cold event will affect the grape harvest.

Chang says bud damage alone is not enough to make accurate predictions. Rather, it’s when the vines flower in late May or early June that scientists can see more accurately how the bud damage will impact the coming grape harvest.

Winegrowers Advocating For Large Scale Replant Program

In the meantime, Winegrowers of BC is working with the BC government to create a widespread replanting program in the Okanagan and Similkameen Valleys, and not just because of this latest frost event.

The Vineyard Resiliency Report in 2022 was created because growers could see the long-term impact of climate change, which led to the long-term decline in crop yields since 2013.

Prodan says one thing that became clear is that the grapes planted in the region 30 to 40 years ago are not going to perform well in the more extreme weather events brought on by climate change.

“With this (Vineyard Resiliency) report, we were able to quantify what the problem was,” Prodan said. “And so we’ve been talking to government about a replant program for the grape wine industry, because what we need to do is replace some of our vines that were initially planted 30 to 40 years ago, when the first free trade agreement went into place and made California wines more accessible, more inexpensive.

“And so the industry did the big replant program back when they took out all the hybrid grapes and planted the vinifera for grapes, but we didn’t really know what we were doing back then,” Prodan explained. “I think we’re seeing part of the decline in the crop is due to, for sure, climate change, but it’s also just that we need to update as we may have planted the wrong grape in the wrong place, and I think with climate change that’s really starting to be exacerbated.”

WGBC has since asked the BC government to include funding for a replant program in the 2023 budget, which was announced on Feb. 28.

A government official told Orchard & Vine that, while no funds are specifically earmarked for a wine grape replanting program, “The details around specific programs to be funded out of supplementary funding will be announced in the coming weeks and months.”

As well, a source of potential funding for an emergency replant program could come from the $160 million set aside in the 2023 budget for BC’s Food Security Initiative.

BC Wine Industry Will Need Short Term And Long Term Aid

Prodan says there are two major issues facing the industry this year.

The first is that the Vineyard Resiliency report showed the grapes currently planted in the Okanagan and Similkameen regions are not resistant to extreme weather events brought on by climate change.

That is why WGBC is already pushing the BC government to fund a large scale replanting program.

However, thanks to the extreme cold snap starting on Dec. 22 last year, growers and winemakers will face an immediate crisis if the crop yields fall by another 30 to 50 per cent. Even worse, if trunk damage is also widespread, the reduction in crop yields will continue far beyond the current season.

Prodan says growers are just starting to talk about what they can do should the worst occur.

The obvious answer for trunk damage would be a massive replant program, ideally with grapes capable of withstanding extreme weather events.

The tougher question is what to do if there is a major crop failure in 2023.

One answer, which would be extremely controversial, would be a short-term exemption to the BC VQA regulations, which state that only wines made solely with BC grapes can qualify.

Will BC Need To Suspend The VQA Program?

Non-VQA wines are treated differently in terms of taxation and how they can be sold, which helps support estate wineries by increasing their profit per bottle.

However, if there are not enough grapes to produce VQA wine at the needed levels, one solution would be to import grapes from other wine regions; a plan that would only work if the BC government waived the rules and gave wineries the same tax and price breaks as they currently get for VQA wines.

The Ontario government, which has its own VQA program, did something very similar when growers there suffered a catastrophic drop in yield for similar reasons in 2005. In that case, the public was informed through changes in labelling, and the strict regulations of the VQA program were brought back in 2006.

That move saved an estimated $150 million in losses to the Ontario wine industry.

Prodan admitted the topic has come up, but said it’s not something anyone wants to do unless the yields really are catastrophic.

Yeah, sure, we’re looking at that Ontario model,” Prodan said. “I mean, this is premature, and we haven’t been in formal discussions, but what about taking a look at maybe allowing wineries to access some sort of grapes from other regions, right?

“If we have wine to process and there aren’t grapes here in BC, what else can we do? Can we bring some limited amounts in from Ontario? Can they bring some limited amounts in from Washington State and what does that mean to the BC VQA, which is a brand that we’ve been working so hard to maintain and champion?

“So these are some of the high level discussions we’re having right now, but until we can substantiate the potential extent of the damage in terms of economic impact and the rest of it, it’s a bit of an academic discussion, but it needs to happen and it is happening right now.”