Drought, frost, heat blamed for light Mendocino County wine grape crop
Vineyards in Potter, Redwood and Ukiah valleys may be more heavily impacted by the reduction in grape tonnage this season than other North Coast appellations from the second straight year of drought, but Mendocino County’s crop size could also be impacted by frost, according to market watchers and growers.
“That’s a lot of acreage and tonnage,” said Christian Klier, a North Coast wine grape broker for Novato-based Turrentine Brokerage, about potentially affected vineyards in those appellations.
Common tools for estimating crop size are counts of clusters per vine and weights of clusters, but what the harvest tonnage actually is won’t be known until the fruit arrives at wineries over the next few months. And the total crop size won’t be known officially until the state crush report is released in early February.
“Some are talking about it being down 15% to 20%, with some varieties off 30% to 40% and some about normal,” said Bill Pauli, general partner of custom vintner Yokayo Wine Company and a partner in affiliated growing company Pauli Ranch.
Pauli Ranch farms 1,400 acres of vines, mostly in Mendocino County, with scant acreage in northern Napa Valley and on the east side of the Russian River near Cloverdale.
Lake County sauvignon blanc and Mendocino County pinot noir seem most affected at this point, down as much as 40% in potential tonnage from the multiyear average, but cabernet sauvignon yield doesn’t appear to be off by much, he said. But the company’s cab clusters north of Calistoga appear to be weighing in 10%-15% less.
Potter Valley received just shy of 19 inches of rain through the current water year, a record-keeping metric for how much precipitation comes from October through the following spring and summer growing seasons. That was just 41% of the valley’s historical average and follows the 2019-2020 water year with rainfall less than half of average, according to the National Oceanic and Atmospheric Administration.
The drought has spurred state water regulators on Aug. 10 to expand an earlier halt to diversions of water from the Russian River basin, ordering over 300 more grape growers, ranchers and other property owners to stop doing so as of the next day as the region’s reservoir levels dwindle, according to The Press Democrat.
The new limits affect a Sonoma County water-right holders from the Dry Creek Valley and other tributary areas around the middle reaches to the lower part of the river.
Regulators told the publication that there appears to be skirting of late July order on more than 1,500 water rights holders in the upper river. The officials point to water gauge data that shows little change to the amount of water that’s released from Lake Mendocino to the upper river making it down to the lower parts of the river.
Lake Mendocino has fallen to its second-lowest level since the late 1970s drought and nears the minimum target level of 20,000 acre-feet for the end of the water year. As of Aug. 8, the reservoir level was just over 23,000 acre-feet.
An acre-foot is a water storage metric equal to about 326,000 gallons, or enough to nearly cover a football field 1 foot deep.
“There was unevenness of the vineyards in growth and set,” Pauli said.
“Set” is the term for when grape vines self-pollinate, setting up development of grape berries for the season. There also were multiple 100-degree days in May, followed by a cooling period and several days of strong winds during set.
At McFadden Family Vineyard & Farm in Potter Valley, it’s looking like a lighter-weight crop, and the lack of rain has been a problem factor.
“We have fewer clusters,” said Fontaine McFadden, head of operations for the grower and vintner, winner of 2021 Mendocino County Fair Wine Competition’s best of show for sparkling wine. “A silver lining is that in years past when we’ve seen fewer clusters those have been wines that were more delicious.”
Redwood Valley Vineyards, a sister company to vintner Barra of Mendocino, farms over 265 acres of organically grown pinot noir, ninfandel, cabernet sauvignon, sangiovese, merlot, petite sirah, chardonnay, pinot blanc and muscat canelli grapes. Proprietor Martha Barra expects the yields to be a quarter to 30% below average for certain varieties, the second year in a row in which the crop volume was down by over 20% on the three vineyards the family owns and operates.
“We have had plenty of water for frost protection and drip irrigation because of the sheet-fed reservoirs on our 250-acre home ranch in Redwood Valley, but our foreman believes the main reason for the short crop is because of the lack of sufficient water during the previous winter-spring season,” she said.