It takes perfect growing conditions to turn the rows of grapevines surrounding Paso Robles into the top-tier wines the area is known for.
David Parrish, a third-generation vintner at Parrish Family Vineyard, has seen the effects of a changing climate firsthand. He showed KSBY News Meteorologist Vivian Rennie how he is protecting his vines.
When asked if he has noticed any changes in growing conditions, he immediately stated, “Oh, it is getting warmer. Yeah, there is no doubt about that.”
Everything from the pH of the soil to the angle of sunlight on the vines impacts the final product. Above all of that, though, Parrish says that heat can be the hardest on the vines.
Already in 2024, record-breaking heat has been recorded across the region with high temperatures soaring above 110° for days at a time. The normal high temperature for Paso Robles Airport in July is 93.3°. July 2024 averaged a high of 100.2°.
For climate data check out this link.
Projections from Cal-Adapt, a statewide climate change assessment tool indicate hotter, longer summers in the vineyards of Paso Robles. Here is a look at the local climate change snapshot for the Paso Robles Creek-Salinas River Watershed:
Parrish recalled conditions when his grandfather was planting the vines and his own experiences in the vineyards as a child.
"I think since I was a little kid, I don't remember it being this hot for, for the long periods that we're having,” he said.
At temperatures above 95°, the vines partially shut down. Too long under those conditions can permanently damage the fruit and the vines. On the day of Rennie's visit to the vineyard, the temperature was soaring.
“I mean, we're 95 degrees at 10 a.m. We're already up to the top threshold," Parrish said.
Just a few miles away at Robert Hall Winery, the higher temperatures have already impacted the way grapes are grown.
Caine Thompson, Managing Director of Robert Hall Winery and Head of Sustainability at O’Neill Vintners & Distillers, says that while they used to need to protect against long cool spells, that's no longer their focus.
“The climate has warmed," he said. "We don't necessarily have a problem with ripening per se, so you've seen a move with cordons being raised so fruit [is] higher up and so it's further away from that heat, from the ground. [It] also helps provide a larger canopy for the shade and protection.”
That shift is part of the practice of regenerative organic farming for Robert Hall and O'Neill Estate Vineyards.
They are implementing these practices at scale in their vineyards and working with other wineries across California for even larger-scale implementation.
“What we are trying to avoid is too much sun exposure onto the fruit. So we've found with regenerative farming, with the larger canopies that we're growing we're getting these like almost like umbrellas over the fruit that's protecting the fruit, so more of the fruit is staying intact. We've got this beautiful balance of sweetness and acidity in the fruit that allows us to make premium wine here in Paso,” Thompson said.
Pairing the larger canopies with natural ground cover, vines on higher cordons and even incorporating animals like sheep grazing in the vineyard makes for healthy vines.
"It's all these little techniques that make a difference when we're farming for the future,” Thompson continued. "What we need to think about is how we manage our canopy and how we manage our fruit to ensure that the same flavors and phenolics, etc. get stored within the fruit as it has for the last 50 years in Paso Robles of wine growing.”
At Parrish Family Vineyard, they are also shifting how grapes are grown with an invention right from the mind of David Parrish. They have implemented a system of shade cloths covering the fruit on the sunny side of the vines.
"Heat and the direct light can cause the grapes to heat up so much that they'll start wilting and of course, U.V. causes sunburn on the skin. Once that skin starts to crack, there is no way. I don't care if I poured buckets of water on the grapes, they just keep going south because once you start that dehydration and split skin, the fruit is toast. So that's where the shade cloth comes in is that we're mitigating some of this heat," Parrish explained.
The innovations being implemented across the region like shade cloths, row orientation, cordon height and irrigation protect the vines but Cal Poly Professor Dr. Nick Babin has already seen more long-term shifts while conducting his research.
“I talked with grape growers who are considering, you know, putting in mescal plants and, you know, agave and things that are very heat and drought resistant," he said.
Water availability, severe heat waves, and warmer nights are expected to become more of a problem in the coming decades.
“The scary part is, is that down the road the varieties that are being used in Paso Robles, based on the projections of projected change, won't be very apt to be grown in Paso Robles," Babin said. "So long term, the impacts could be as much as no more wine grapes or a completely different type of wine being grown there, which, you know, has its challenges because they're known for certain varieties. You know, the Cabernet Sauvignons and somewhat Merlots and so yeah, that'll be a big change I think, but maybe in the next generation before we see that.”
The French varieties found across the Paso Robles hills aren't the only option, though.
"You're talking about varieties that are grown in like Syria and, you know, places where it's warmer and hotter, so southern Italy, right? Most of the varieties that are currently grown are French varieties. And, you know, the further I mean, there's plenty of opportunities and available varieties. It's, again, a branding thing, right? People know what Cabernet Sauvignon is [but] they might not know this variety that has a name they can't pronounce and it's, you know, from a hotter and drier place,” Babin said.
Across the board, vintners are taking on the challenges as they come season by season and day by day.
When Dr. Babin spoke to wineries about the projected changes for this research article,responses were varied.
“Honestly, many of the growers, when I talked about projections were kind of if they believed in the projections, they gave me their opinion and I asked them, even if they don't, you know, just play along, what would this mean for you?" he recalled. "There were many who said, 'Well, we won't be growing grapes here anymore.'”
Into the future, Parrish will continue to adapt.
“It’s not one silver bullet," he said. "It's not just the shade cloth. It's watering, it's your canopy, how you arrange your canopy, it's how you thin your grapes, how you pull the just the right amount of leaves, the tunneling. I think the shade cloth is, is in addition. But it's all of those. And if you miss any of those steps, you know, Mother Nature will remind you, so it's something you have to be out here all the time.”
