Paso Robles, Calif.—In the weeks since a frost event battered coastal vineyards from Santa Barbara to Monterey counties April 8 and 9, buds have failed to push out and sucker growth has popped up. Overall, many predict that the region’s 2011 crop will be down 30% as a result of the freeze.

Vineyard managers reported that standard frost-protection measures were not effective in combating the frigid temperatures, which surprised many by striking some high-elevation regions harder than the low-lying valleys that are often worst hit by frost events.

The most damaged area follows a 60-mile swath of Highway 101 from Templeton north to King City in Monterey County. During the 1970s, developers started installing wind machines as the primary frost protection program for Central Coast vineyards; few vineyard acres are protected by overhead sprinklers.

At the time of the mid-April freeze, there was no inversion layer of warm air above, and wind machines designed to circulate warm air down into vineyard rows proved ineffective: They circulated only more frigid air.

Temperatures dipped below freezing before midnight and stayed there until early morning. Dana Merrill, who owns Templeton, Calif.-based Mesa Vineyard Management with his wife Marsha, said that temperatures in some areas dropped as low as 24ºF; other zones were pounded with hail.

Surveying the scene
Richard Smith, president of Valley Farm Management in Soledad, told Wines & Vines that the April freeze marked the first time in 39 years that he’d had notable damage from frost. About 300 of his 3,000 vineyard acres were damaged by frost—all of them planted to Chardonnay.

Smith turned on his frost protection at 9 p.m. and ran it until 9 the next morning. Typically it isn’t turned on until at least midnight, and more often from 4 a.m. until 7 a.m.

“I’ve had more damage on the benchland than on the valley floor (100 feet below), and that’s what’s really screwy. We had pockets of air that moved around,” he said. “The 100 acres on the benchland were devastated. It looks like someone went through with a torch.”

The freeze surprised many growers, according to Stacie Jacob, executive director of the Paso Robles Wine Country Alliance, who added, “We had great rain, and we had some really warm weather before the frost hit. The vines were pushing and next thing you know we get zapped with a cold spell.

“It was one of the hardest frosts we’ve had in quite some time,” she said. “Some vines will need to be cut back down.”

The area’s No. 1 grape, Cabernet Sauvignon, wasn’t budding out at the time of the freeze, but frost conditions still killed a good number of Cab buds across the 27,000-acre appellation. Merlot (the No. 2 grape in San Luis Obispo County) fared a bit better. Merrill said that Rhône varieties such as Viognier and Grenache were hit hardest. “Syrah is growing again, but there are no grapes on it,” he said.

Goodbye 2011 vintage?
In the Hames Valley AVA where Smith experienced frost, a second crop has come in, which he said will probably comprise no more than half the original set.

According to Merrill, who tends about 6,000 acres between Santa Barbara and Monterey counties, most of the region’s grapegrowers were already under contract for this season, and prices were starting to bounce back from the past few years of recession.

“A lot of people are kind of in shock—especially the newer growers. Prices are finally getting better, and then this happens,” he said. “2010 was a big-yield year, so we’re going to go from a big yield year to one of the lightest. There is going to be a very noticeable drop.” He estimated that growers may lose an average of 2 tons per acre.

Both Jacob and Merrill emphasized that about half of the winegrapes grown in San Luis Obispo County are bought by wineries outside of the area, so while some sources predict that the possible crop loss due to frost could be as high as 50%, wineries within the county should not have trouble sourcing fruit.

It’s not as if there will suddenly be no Paso wines on the shelf, Jacob said. “We were really a grapegrowing region first,” and the area was built on solid relationships. “So I think those folks (from outside the region) that look to Paso for that inexpensive, high-quality fruit, that’s potentially the area that could be hurt this year.”

In the meantime, Merrill said, there is nothing to do but wait. “We just have to see what we get out of these grapes. In a lot of ways, we’re farming the 2012 crop now. The 2011 crop is gone and we’re just raising a vine,” he said.