The El Dorado Agricultural Commissioner Reports Significant Crop Damage From Recent Frost. The Agriculture Department is working on the tabulation of data from El Dorado County farmers and ranchers for a disaster declaration due to drought and extremely low temperatures a few weeks ago. The information gathered from growers so far suggests that the entire cherry crop and peach crop has been lost. Apples, some varieties of grapes, Asian and Bartlett pears and walnuts have been damaged as well. Rangeland has also been hit very hard due to the drought and low night time temperatures. Damage to Grape has also been observer locally.
Damage pictured is on the editor's vines at 1500 foot elevation in Placerville from last week's cold snap.
Ooh, that's cold - Local wine grapes pinched by unseasonable April frost.
By Jerry Budrick,
Amador Ledger - April frosts are threatening to destroy a significant percentage of the county's primary source of agricultural income - grapes.
Having passed cattle and calves years ago, grapes are an important part of the local economy. Vineyards cover more than 2,700 acres of Amador, yielding revenues of more than $15 million. Most local grapes are grown in Shenandoah Valley, northeast of Plymouth, at elevations between 1,200 and 2,000 feet. The terrain is varied, with hills and valleys interspersed with woodlands and wetlands to create numerous microclimates.
Farming is known to be a risky business. Grape farming in California is among the riskier, in that the 180-day growing season is longer than the relatively risk-free time between frost and rain.
Grape growing in the Sierra Foothills is also a risk-reward business. The risks with the weather are weighed against the reward of high-quality grapes and grape prices reflective of their quality. Popular varieties of red wine grapes in the foothills, such as zinfandel, barbera and syrah, command prices two or three times as high as their counterparts grown in the safer climates of the Central Valley.
Timing is everything. If a frost hits at just the wrong time, half an hour is long enough to kill the young shoots. An entire night of frost will almost surely kill them. The three weeks in April of intermittent freezing temperatures have hit the grape industry in numerous parts of California. Reports from the North Coast, which includes Napa and Sonoma valleys, estimate losses as high as 10 percent of the $800 million crop. In the foothills, a few vineyards in Amador's neighboring counties of Calaveras and El Dorado have been wiped out. Frost is very selective.
Veteran grape grower Frank Alviso, of HFH Ranch and Clockspring Vineyards, has been in the trade since 1974. "Frost can have the same killing power as a blowtorch," said Alviso. "The cells are ruptured by either heat or cold almost equally. Heat's much faster, but frost is similar."
There has been some damage in Alviso's muscat and syrah vineyards, although precise assessments are not yet available.
Alviso tells a bittersweet story about his first Amador experience with young vines, frost and a grizzled local ranching veteran. Pursuant to his plan to grow many acres of grapes off Steiner Road, Alviso had started hundreds of new vines in the valley behind the old Shenandoah Valley Cemetery. Having lived in California's Central Valley nearly all of his life, Alviso was hardly accustomed to frost at all, let alone in May. So it was that his tender young vines got zapped by freezing temperatures on the nights of May 19 and 20, 1974.
In a conversation with local Amador rancher Herb Farnham, Alviso asked if that sort of thing happened often around the county. As Alviso tells it, Farnham thought about that for a while, then responded, "I do remember this happening before. It was the year my brother went off to the war. Yes, that was it. May 21st, 1918." Alviso recalls thinking at the time that if it happened only once every 50 years or so, he could live with it. "We farm by overreaction," Alviso added. "We put in sprinklers, a wind machine and smokeless orchard heaters (the three generally recognized frost protection devices)."
At Cooper Vineyards, Dick Cooper has set up frost protection provided by huge 50-foot wind machines that resemble the wind generators seen in passes through the coast range of California. Simply put, cold air falls, so grapevines in swales are more susceptible to frost. Wind machines, many equipped with automatic thermostatic starters, are set to come on at 35 degrees, protecting against inversion and its killing frost.
Twenty-five years ago, Cooper's father told his son that killing frosts come every 12 years or so. "I asked dad when the last killing frost had occurred," Cooper remembered. "He told me that it had been 10 years." Armed with this frightening knowledge, Cooper found two used "low-profile, inexpensive" machines, which he set up in the vineyard.
Two weeks later, frost came falling in. Cooper speaks of firing up the tremendously noisy machines, "saving three out of five acres in the hilly vineyard." When the ordeal was over, "the areas where the wind hadn't reached looked like cooked spinach," recalled Cooper, "while the vines where the wind reached were just fine."
Now, Cooper has six wind machines in his vineyards. This year's frosts have triggered the machines nine or 10 times and the machines have prevented frost damage. Protection does not come without cost. Propane to run the motors that drive the wind machines can be as high as $1,400 per night.
Grapevines are among nature's sturdier creations, capable of surviving bitterly cold winters. They are usually fairly intelligent, as plants go, hibernating in a state of dormancy until the danger from frost is past. Established grapevines in California are almost never destroyed during the dormant period by cold temperatures.
There is, however, a time of vulnerability, when grapevines are waking from their winter's rest. First to appear in spring are tiny buds near the tips of the vine. The buds are rather shy and careful, still protected by layers called scales. "Bud break" is the moment in spring when the protective coating of the new bud opens up, the scales spreading like the lens of a camera, allowing emergence of the delicate new leaves and, subsequently, the miniature grape clusters.
Sobon Estate Winery is higher in the Shenandoah Valley, with vines planted at elevations around 2,000 feet. Damage to barbera, syrah and rousanne vines has been extensive, perhaps 50 percent of the crop. "The true extent of damage won't be known for five or six weeks," says Leon Sobon. Sobon had planted barbera on a slope he thought would have natural air drainage adequate to provide frost protection.
"Zinfandel is the last to bud out," Sobon added. "That's why old-timers planted it."
Jerry Budrick
