At the beginning of April, Calaveras County wine grape grower Matt Hatcher estimated that his 3.5-acre Zinfandel vineyard was about a week from bud break.
“That’s pretty much on time,” says Hatcher, who is starting his eighth season in the vineyard. Situated at the 1,500-foot level in the Sierra Foothills, the buds on his vines typically start pushing about three to four weeks behind those in the San Joaquin Valley, he notes.
He uses these grapes along with a number of other locally-grown varietals to make wine for his Hatcher Winery label. As a Zinfandel grower, Hatcher is following in the footsteps of the pioneers who planted the area’s first Zinfandel vines during the Gold Rush days of the late 1840s.
Zinfandel vines, Hatcher says, stand up to freezing temperatures better than many varieties. “Frost is very common here until about mid-May. In 2008, following a hard, late freeze, a lot of vineyards with other varietals produced 1 to 1.5 tons of grapes per acre. But Zinfandel is so vigorous that we didn’t have to drop any fruit in our vineyard, which yielded almost 3 tons per acre, our normal production. The next year the vines tried to make up for damage from the frost and we had to keep dropping fruit and we still harvested our usual 3 tons per acre.”
Because of the small size of his vineyard and limited water supplies, Hatcher has no frost protection program for his drip-irrigated vines. Instead, he relies on pre-pruning in January to help his vines better cope with spring frost. When pre-pruning he leaves about 12 to 14 inches of cane. In April, after the very top buds have produced about 1 to 2 inches of new shoot growth, he then cuts the canes back to just two buds. That delays new growth a bit longer. “That gives us another 10 to 14 days of frost protection,” Hatcher says.
Once the new shoots from these buds have grown 3 or 4 inches, he goes back into the orchard to thin any shoots produced by the basal buds.
Normally, powdery mildew isn’t much of a problem for Hatcher. “We’re pretty fortunate,” he says. “We have relatively dry weather, and if we do have any disease problems, we get right on it.” To help fend off mildew and mold he treats his vineyards with sulfur every 28 days, beginning when the new shoots are about 6 to 10 inches long until August. Then, he switches to a different fungicide.
To help his vines better cope with the challenging conditions of his low water-holding gravelly soils, arid conditions and a lack of groundwater, Hatcher has been treating his vineyard three times a year for the past three years with a fertilizer product containing various micronutrients. He applies it through his drip irrigation system. Called RootMASTER, the product may increase vigor on growing plants, says Reed Smith, a multi-disciplinary ag researcher from Modesto, Calif. The product is the result of his 25 years of research screening non-traditional chemistries for use on various crops.
Hatcher has been using it to improve the canopy and root systems of his vines. “The vineyard looks much healthier since I’ve been using the product,” he says. “Healthier vines do a better job of producing grapes and encourage a more efficient root system that can store more water. I don’t have to irrigate as much.”