North Coast vineyard labor shortage opens more to mechanization

A crew from Harvest Pro Mechanical of Santa Rosa runs pruning equipment through a North Coast vineyard. (HARVESTPROMECHANICAL.COM)



As April showers add to the already full cup of needed moisture for the 2017 North Coast winegrape season, growers have been busy doing more work in the vineyard at a time of fewer workers available for those tasks.

For the past few years, farm workers have been in shorter supply, no thanks to competition for jobs from other industries, such as construction, and changing government policies toward farmworker immigration.

Science and experience has led to more tasks in the vineyard before the fruit ever reaches the winery. Of the major vineyard tasks during the growing season, roughly half are relatively new, and many remain hands-on work, according to Duff Bevill, owner of Bevill Vineyard Management, which farms hundreds of acres in Sonoma and Napa counties.

“Even in spite of mechanization, which has dramatically dropped the cost of harvesting, we have created over the past two decades so many more tasks in the field that were driven [by] wine quality or for disease control and done by labor,” Bevill said.

To the age-old processes of pruning, suckering (removal of root sprouts from the vine trunk at the ground level) and harvesting have come several tasks under the category of “canopy management” — crop- and shoot-thinning, shoot-positioning, hedging, and removing leaves. Other new tasks are irrigation fine-tuning and crop data collection.

These added tasks have made vineyards in the North Coast and close competitors hot targets for grape contracts and property acquisition, particularly as many major players in the wine business are fast shifting focus to higher-priced wines.

But these enhanced viticultural practices come at an enhanced cost, Bevill said. In the hierarchy of labor-intensive vineyard farming expenses per acre are harvest, pruning, crop-thinning and leaf removal, Bevill said.

“Harvest always is first the discussion, because historically it is the most labor-intensive task in the field,” Bevill said. “Forty years ago, labor was 65 percent of the farming production cost, and it is still that way, if you do it by hand.”

Mechanized harvesting, used for years in higher-production areas of California, has been gaining momentum in higher-value wine regions such as the North Coast in the past few years, largely because of labor availability. Better technology for gentle treatment of the clusters coming off the vine and less “material other than grape,” or MOG, arriving at the winery has helped convince some winemakers to accept that mechanization.

Though used in Australia and Italy for many years and increasingly in the California interior, mechanical pruning is just making inroads into the North Coast. Bevill said a vineyard his company manages was machine-pruned for the first time this winter, four years after the trellis system was set up for the box-pruning style needed for the machinery to work beset.

In addition to the configuration of existing trellises, other obstacles to mechanization remain. Hillside vineyards can have soil and moisture conditions that put just the right amount of stress on vines to coax out desired quality, but the slopes also can challenge operation of tractor-mounted equipment. And equipment that best meets the quality targets for North Coast vineyard operations may not be readily available in stock equipment, requiring ingenuity from fabricators for custom attachments, Bevill said.


They’re all intended to maximize the vine’s efforts in producing fruit winemakers want, while helping to prevent conditions they don’t, such as “sunburned” grapes, less-concentrated color and flavor, and disease.

Removal of shoots from vine cordons — “arms” extending to the side from the trunk — early in the season helps limit the crop size by reducing the number of places the vine where can flower and later form clusters. This ultimately helps direct the vine’s energy toward fruit vs. foliage.

Shoot-positioning is how the remaining vine shoots are tied to a particular style of trellis. Like pruning, training vines to grow in a desired way dates back to antiquity. For example, Pliny the Elder wrote in his 37-volume first-century “The Natural History” that grape vines should be trained up trees, but examples of Roman vineyards included use of stakes for training in fields without trees.

Several types of trellises to match the growth patterns of a grape variety and the growing environment of a particular vineyard have come out of research and experimentation in Europe, U.S., Australia and other winegrowing regions of the world in the past few decades.

Crop-thinning is a vineyard task after clusters are ripening to remove underdeveloped or excess clusters — or even individual less-than-ideal grape berries in fruit bound for high-end wines. A number of North Coast vintners have installed staffed or automated sorting tables to further select the quality of fruit going to a particular wine.

Hedging of vines is also called caning, because the vine canes — shoots turned mature wood — are pruned postharvest to prepare “fruiting canes” for the next season.

Leaf removal helps growers balance a critical need for vine survival with As with other plants, grape vines need their solar panels — leaves — to power photosynthesis, the transformation of nutrients and water from the soil plus carbon dioxide from the air into fuel for growth and ultimately fruit production.

Growers don’t want too much vine vigor going into foliage, and a certain amount of sunlight helps grapes cross the maturation finish line for harvest. And too much sun exposure on hot days can “sunburn” grapes, leading to poor color development in red varieties such as cabernet sauvignon and merlot, and brown lesions on the berry skins of white varieties such as chardonnay and riesling, according to researchers from Washington State University.

Yet too much foliage can reduce air circulation around the clusters and increasing the likelihood of mold on days with too much moisture.


Leaf-removal equipment has advanced considerably in the last five years, allowing mechanization of that task to likely become a more accepted method, regardless of the price of the grapes, according to Eric Pooler, vice president of winery relations with Silverado Investment Management Co.

“Necessity breeds innovation,” Pooler said. “Wineries have allowed processes occur mechanically that had been done by hand in the past, when labor gets tight.”

Silverado is a Napa-based arm of Winchester Agricultural Asset Management, itself part of New York-based TIAA-CREF Life Insurance Co., and oversees a portfolio of about 21,000 acres of vines in California, New Zealand and Australia. Silverado has about 5,000 ultrapremium-oriented acres in the North Coast, including about 700 acres in development, ranging from new plantings to those reaching commercial maturity.

Its Central Coast vineyards tend to be larger in size than those in the North Coast, so they’re more often set up for more mechanized tasks, according to Matthew Parker, Silverado vice president of acquisitions and sales.

“If develop a new vineyard in Napa and Sonoma [counties], we do set them up to be mechanized, but that does not necessarily mean they will be, because of winemaker acceptance,” Parker said.

There’s more mechanization of vineyards in New Zealand, where programs to bring in workers from South Pacific islands still doesn’t create a large labor pool, he noted. And Australia has a similar situation.

Silverado’s investment mandate is to focus on coastal California, New Zealand and Australia, and concerns about cost of labor do affect the company’s decisions on where to put its funds, Parker said.

The cost and availability of labor likely will demand that more work is done by machine for lower-priced grapes, concentrating labor on high-touch, higher-priced fruit, Pooler said.

“There has to be a winery paradigm shift,” he said.

Parker and Pooler are set to speak at the Business Journal’s April 28 Wine Industry Conference on the labor shortage for the wine business and potential solutions. Options include H-2A guest-worker visa reform, more mechanization in ultrapremium vineyards to increase yields, adjustments to accommodate more women getting into field work, and reconfiguration of cooperatives as a workaround for new state rules on hours worked per day.

Jeff Quackenbush (, 707-521-4256) covers construction, commercial real estate and wine.