Hanzell Winery’s sprawling vineyard is nestled atop the Mayacamas Mountains in Sonoma, California, where volcanic soil has fueled continuous production of chardonnay and pinot noir for decades. The property, punctuated by postcard imagery and mature foliage, is 200 acres, and 46 of those are planted to vine. While the vast majority of commercial vineyards are examples of monoculture — raising no animals, vegetable crops, or other food products — Hanzell takes a contrary approach, embracing the biological benefit of having animals and plants interact with its soil.

Four years ago, Hanzell president, farmer, and winemaker Jason Jardine elected to introduce pigs, chickens, sheep, ducks, and geese to his property. “Of all the world’s ecosystems,” he explains, “the symbiotic relationship between animals and plants is absolutely critical to sustain the life of the soil and the health of the wine. Plants react differently based on the manure, urine, bacteria, and fungi associated with native animals.”

This arrangement, however, is seldom executed in the commercial winemaking world. And for good reason: while there are undeniable benefits to renewing soil fertility through a variety of native animals — not to mention the avoidance of composting, which contributes to global warming when practiced at this scale — any animal ecosystem is intrinsically vulnerable, and therefore requires vigilant protection. At Hanzell, predatory menaces include hawks, falcons, mountain lions, wolves, bobcats, coyotes, and the occasional bear that would — for lack of a more delicate term — make mincemeat of the cuddly animals that contribute to this sort of environment.

“They scan the skies during the day and will bark off hawks,” says Debra Peterson, Hanzell’s marketing manager, who handles day-to-day operations at the vineyard. Jardine adds, “They’ll bark at anything they perceive to be a threat to the herd.” The dogs’ heft and strength — Radley weighs more than 120 pounds, and Scout is about 100 pounds — enable the duo to confront would-be marauders when barking isn’t sufficient, and neither will hesitate to jump a fence and chase off threats. “No coyote is going to take on those two dogs,” Peterson says. “There’s not a lot that would protect [the animals] if we didn’t have the dogs, and we’re not the kind of farmers shooting coyotes or taking out predators. We feel they’re just as important, and have a right to be there, as everybody else,” she adds.

Hanzell’s property is fenced off in tenth-acre parcels, encouraging animals to graze in concentrated areas, also known as “mob grazing.” By confining the critters to discreet sections of land, and rotating between sections every other day, the animals are able to feed in and fertilize a specific area without overgrazing that spot, which can be easily patrolled by Radley and Scout. The sheep chomp on surface greenery while pigs perform a light turn of the soil, which churns up worms that are subsequently eaten by ducks. The ultimate goal is to rotate through all 46 acres in one rainy season, but meteorological unpredictability can get in the way of the best-laid plans. For instance, this past winter rain materialized later in the season than usual, followed by a warm and dry February; as a result, bud break on the vines occurred earlier than usual, and the animals had to be moved from the vineyard to the paddock before they could be tempted to sample the fresh buds.

Breaking the routine can be devastating to a Maremma. When Radley was neutered, he was isolated for several weeks and fell into a deep depression that was relieved only when he could see sheep, pigs, or chickens through a fence. “He would just perk up immediately and start pacing back and forth,” Jardine remembers. “Where most other dogs wouldn’t care, they are the opposite of that. They need that environment to thrive.”

The dogs are selfless overseers of the animals, with an unflinching ability to do the right thing, regardless of circumstance. Consider the times when ewes were lambing, and occasionally left a newborn with one of the dogs overnight, who watched over the lamb until one of the farmers took over the next morning. “We would be losing these animals all the time to predators,” Jardine says. “It’s just such a unique bond that Maremmas can make with animals.”

By keeping predators at bay, the Maremmas seem to be having an impact beyond the paddock, as native insects, rabbits, and turkeys flourish, helping to fertilize the soil both within and beyond the contained grazing system. The cover crop that grows following the grazing period creates a thick mulch that locks moisture in the ground and enables irrigation to be reduced by as much as 80 percent, which conserves groundwater.

Long after the grapes are harvested and the sun has set on yet another season, one cannot help but ponder the future of this carefully constructed microcosm of animal, earth, and crop. “By about year 10, we’ll probably introduce two more [Maremmas] from the same family,” Jardine says, referring to Radley and Scout’s breeder in Gold Hill, Oregon. “We’ll retire Radley and Scout, but they’ll stay out there with the animals and remain part of the system, letting the young bucks take over and play that key role of guardians.”

Jardine is quick to emphasize that Hanzell’s Maremmas are the singular element that brings these seemingly incongruous forces together. “Dogs are the absolute key pillar that holds all this up,” he insists. “Without them, you just couldn’t do it; it would be impossible.”