Mowers of choice

Last week, along the steep curves on the approach to the Artesa winery, car after car slowed to a crawl, then to a complete stop – to gawk. Dozens of wooly, white sheep were ambling among the grapevines, heads bowed as they appeared to be in the process of consuming the entire hillside.
But no, they were merely nibbling the grass and other ground cover down to a nub. Organic to the nth degree, letting sheep graze the vineyards and other commercial terrain in wine country is a craze that has caught on over the last decade.
Think of it as “lawnmowers in sheep’s clothing.”
Several Sonoma Valley wineries have availed themselves of the services of Rocky Mountain Wooly Weeders, a Colorado-based company that leases its ovine army for weeks at a time. Starting in February, the sheep continue keeping down the undergrowth through April or even into May, depending on when bud break occurs on the grapevines.
According to company founder Don Watson, “We can make almost any grassland look like a golf course in a matter of days. We use ‘cell’ grazing techniques to remove frost and fire hazards, but noxious weeds are our specialty.
“We are able to leave a healthy biodynamic soil and sward after we leave,” Watson added. “We are the only mowers we know of that mow, weed and fertilize at the same time.”
Some ground cover is desirable, even on flat ground, so some wineries prefer not to disc or till the ground. Too much vegetation can cause problems in the vineyards by competing with the vines for nutrition and water. When the grass grows high, it traps cold air, which can create damage to the lower part of the vine.
Don Clark, vineyard manager at Artesa, said the winery began using Wooly Weeders for the first time in 2007. “What prompted us was, we’re always looking for ways to reduce our use of herbicides and the fuel it takes to mow. Mowers also compact the soil. The sheep are there to help us.
“Before, we were primarily mowing and using some Roundup treatments right under the vines,” explained Clark, who added that the sheep haven’t completely replaced such practices yet.
The cloven-footed sheep are especially suited for hilly terrain, which is a boon to Artesa’s inclines. Running a mower on the hillside can be “a little scary,” said Clark. “When you get to the end of a row and have to turn the tractor around, it’s tricky.” The steepest incline at Artesa is 25 percent, just a hair below the mandated maximum of 30 percent in Napa County for hillside vineyards.
“We bring the sheep in late January or early February and they graze in the vineyards until the buds break out. Then we move them to a hillside outside the (grape) planted area to control vegetation,” Clark said.
After beginning with 200 sheep, Artesa now uses 500, which are deployed in two groups, each contained in a fenced area of three to five acres. Concentration of the animals is key to successful mowing. “They graze intently until the vegetation is down,” said Clark. “If they’re not crowded, they are selective and won’t eat as much. After four or five days, we move them to a new area.”
A portable electric fence keeps the Wooly Weeders from scampering off into the wine country. Keeping an eye on the sheep is a full-time shepherd, who last week was assisted by White Pyrenees dogs who helped ward off such unwanted visitors as coyotes.
The staff at Artesa has concluded that the environmental and other long-term benefits outweighed the cost of leasing the sheep. The story is slightly different over at Infineon. Before hooking up with Wooly Weeders, Infineon tried a variety of options to address the weed problem around the grounds of the racetrack.
For years, Jere Starks, vice president of facilities, employed a combo approach: fuel-powered weedwackers run by employees and cattle that grazed between the raceway and Gate 9 on the far side of the property at the south end of Sonoma Valley.
For one thing, they went through hundreds of weedwackers that not only over-heated but also left unsightly detritus in the form of dead grass. On the other hand, the cows were not contained; every year, they would inflict heavy damage on the roads, which required expensive annual repair. Starks negotiated with a couple of sheep ranchers, but they apparently did not have the right set-up to manage the sheep.
Since Watson’s herd arrived at the racetrack in 2008 – along with their resident Peruvian shepherds – the grounds look almost manicured, said Starks. The Wooly Weeders have grazed the grounds and the parking lot, further enhancing the track’s traffic flow, which used to result in occasional backups as fans had to negotiate the deep ruts left by the cattle. Today, Infineon serves as a central distribution point for the animals, which occasionally go out to wineries under Watson’s oversight. In the case of this entrepreneur, the wool is pulled under his eyes.