As of the third week of July, when verasion started in their Santa Cruz Mountains vineyard, the 2016 wine grape season has been mostly smooth sailing for Dan Martin and his wife, Thérèse.
“Except for several little heat waves, the weather has been pretty mellow,” he says. “The crop is coming on very early, like last year. Although we’ve had very few issues with powdery mildew, crop load looks better than last year. Quality-wise, it could be a good, maybe even a great, year.”
The Martins, both of whom were born and raised in the area of the Santa Cruz Mountains, planted their first vines, Cabernet Sauvignon, in 1993 near Gilroy, Calif. Ten years later, they established Martin Ranch Winery, which produces wines from their 14 acres of estate-grown grapes and from several other appellations in the region.
Grape production at Martin Ranch Winery is divided between two vineyards. In the upper one, they grow Cabernet Sauvignon, their predominant variety, along with Nebbiolo and some of their Cabernet Franc. Several hundred feet down the hillside in their lower vineyard, they produce Pinot Noir and the rest of their Cabernet Sauvignon and Cabernet Franc grapes.
Last year, Dan was surprised by their yields. “When the fruit was piled up in the bins, I thought, ‘We’re good,’ he says. “They looked like they do in a normal year, maybe around 1,100 pounds in a bin. But they actually weighed only 700 to 800 pounds.”
Depending on the year, production across all his varieties ranges from about 2.5 to 4 tons per acre. In mid-July, he was predicting yields this year to average around 3 tons per acre. Closer to harvest he’ll weigh some cluster samples to get a better idea.
So far this season the vines have escaped the damage inflicted during last’s year’s drought when deer regularly jumped the deer-fence surrounding the fields in search of forage, Dan said. “That’s almost never happened here. The bucks will go wherever they want. But normally the does won’t go where their fawns can’t. Not last year.”
While this year’s much wetter weather has provided enough forage to keep deer out of the vineyards, it’s also enabled the natural vegetation within the fenced boundaries to flourish. So far this season, Dan has made half a dozen passes down the rows to control weeds. Prior to bud break he uses his ATV, equipped with a boom sprayer, to treat the area under the vines with Roundup.
After bud break, he uses a backpack sprayer with large-opening nozzles to apply the herbicide, as these heavier droplets reduce the risk of vine-damaging spray drift. In addition, he mows the natural permanent vegetation in the row middles after desirable plants, particularly red clover, have gone to seed.
Although all his blocks of grapes are set up for drip irrigation, only the upper vineyard requires regular watering. There a clay layer limits vine-root growth to a depth of just five feet.
“We haven’t had to irrigate the lower vineyard for the past 15 years,” Dan says. “Here in the mountains soil types can change rapidly within a relatively short distance and elevation. In fact, within our 14 acres of grapes, there are seven distinct areas that differ in types of soil and orientation to the sun.”
Up until a few years ago, the Martins burned their cane prunings. However, because the vineyards lies within what is now classified as an Urban Wildfire Area, he uses a flail mower to chop up the prunings, which are left in place to decompose.
Assuming no big changes in the weather between now and when the grapes are ready to pick, Dan expects the harvest to begin in his area in mid-August with Sauvignon Blanc. He looks for his Cabernet Sauvignon to be ready as usual in the latter part of September.
“I want the fruit to mature to the point where the seeds are brown,” Dan says. “I like to pick the grapes with pH in the range of 3.45 to 3.55 and sugar around 25.0º to 25.5º Brix.”
Achieving that was especially challenging last year, he notes. “Because of a heat wave during harvest, all our varieties came on at once,” he recalls. “We really had to hustle to get everything picked at the quality we wanted.”