In the winter, when the cover crops are tall and green, having sheep in the vineyard is pretty easy. There's plenty of food for them. The dormant vines aren't of interest to the flock, who focus on the grasses and weeds. You build up your soils without having to bring in outside fertilizer. You minimize your tractor passes and the soil compaction and diesel exhaust that come with them. This scene, from a few years back, is typical:
The cumulative impact of the sheep, year after year, has been transformational for our soil. The roughly 200 sheep we have drop some 750 pounds of manure per day. All that organic matter provides nutrients to the vines, but also increase the soil's water-holding capacity. Given that we don't have a water table at any depth that roots can get to, our ability to dry-farm is dependent upon how much water our surface layers can hold. The calcareous soils that led us to choose this property are a great start. But the sheep have been a big help here too, and are key to our ability to farm regeneratively, pulling carbon out of the atmosphere and fixing it in the soil.
The challenge comes in the summer months, when they can't be in the vineyard because they would happily eat the leaves and fruit off the vines. Plus, it stops raining in April and as the grasses dry out the flock's food gets scarcer. If you have to bring in feed from offsite it can get expensive. Plus, sheep are natural wanderers, and can develop health problems if they're kept in the same small area day after day. So, what to do? For most of the past decade, they summered on the block we call Jewel Ridge, which we purchased in 2011 but hadn't started planting until recently. But over the last two years we planted about 25 acres of the 60 or so that were cleared there, reducing our summer grazing space by nearly half.
One resource that we do have is our forest land. It's harder to run sheep in the forest than it is in an open space, because setting up the fences requires more work. But there's nothing about sheep that makes them less happy to be in the forest, and nothing about the forest that makes sheep an unwelcome addition to the ecosystem. Far from it. According to our Shepherd Dane Jensen, hundreds of years ago the forests in California's Central Coasts would have been home to massive herds of grazing animals like deer and elk, and those grazers played a big role in keeping the forests healthy. Rather than let grasses and shrubs accumulate, competing with the larger trees, grazers turned that biomass into manure, which got incorporated into the soil. With the arrival of European settlers, land was subdivided and fenced off, the migratory herds of grazing animals hunted for food, and fires (another natural part of the ecosystem) repressed. Forests got denser and shrubbier, which in the 21st Century combine with the warming climate to make the fires that do start more dangerous and destructive than ever.
Re-enter our flock of sheep. Last summer we started grazing them in some limited forest areas that we could enclose. This summer, we've started cutting fence lines through the denser growth so they can get into areas we couldn't touch last year. It's been amazing watching them work. They clear the invasive grasses, the shrubs, even the poison oak. This photo shows them in their first day in a new block, attacking the poison oak with gusto:
After a few days, they've turned those dry surface plants into manure, and eliminated some of the competition for the oaks. Plus, their work will help that land absorb more of this winter's rains, which will further strengthen the oaks. Check out this "after" photo of the flock in a forest block, with Bjorn the Spanish mastiff typically sleepy as he usually is in daytime. At night he's on high alert, protecting his flock from mountain lions and coyotes:
In the vineyard, we move the flock daily, mimicking the natural patterns where herds or ruminants stay together for safety (the origin of the term "mob grazing") but migrate based on the pressure of predators so that they don't stay anywhere long. In the forests, we enclose a somewhat larger area of a few acres at a time, but still move them every few days, making sure we don't over-graze any section or neglect any others. We know that doing so is good for the forests, and just as importantly, good for our fire risk.
Based on the questions I get, I think that a lot more wineries would have sheep to help with weeding in the winter if they could think of what to do with them in the summer. Here's one suggestion: look to your forests.