Winter Rain and its Implications – Drought, Weeds and Sheep

A panelist at Rhone Ranger’s 2016 San Francisco Seminar said it best, “there is only one vintage in California, and that is Napa Cabernet.” One only needs to look back to 2011 to find a prime example. Sections of Napa Valley received 5 inches of rain during Cabernet harvest. That same storm brought less than .5 inches to the greater Santa Ynez Valley, yet California’s entire vintage was downgraded.
And now Northern California has received torrential rains, finally something to talk about after 5 years of blissfully boring weather. Ballard Canyon, now at 25 inches of total winter rain versus a historic average of 17, stands at about 1/3 of the precipitation received in the heavier hit Northern California AVAs.
As Californians, we are thrilled to see a wet winter and a healthy Sierra Nevada snowpack.

Effect on Stolpman Vineyards’ Microcosm
In our vineyard’s ecosystem, the drought prompted concern about the nutrient levels in our topsoil and the long-term viability of withholding irrigation from fruit-set through harvest. While we celebrated five epic vintages in terms of wine quality from 2012 through 2016, our winemaking team kept a close eye on lower nitrogen levels of harvested fruit.
The healthy rainfall has brought back a verdant cover crop mixed with weeds and the sub-soil is still nicely saturated with water. For the first time, we might be able to completely dry-farm the entire vineyard.

Because of the plentiful green growth on the vineyard, we allowed a friend to bring in sheep to eat our weeds. We don’t employ animals fulltime as, in this region, there is nothing for them to eat after they consume the winter weeds. They must be sustained by either watering pastures or importing hay. We also prefer to precisely time weed removal with the termination of the season’s rain, so as to regulate the amount of water the weeds take versus what is left for the vines to drink. Unfortunately, sheep can only eat so much every day, and our John Deere’s can swiftly disc most of the vineyard.
After our wet winter, we figured we had more food than normal for the sheep, so we gave them a shot. It turns out these bad sheep couldn’t resist the urge to scratch themselves on our upright training posts, bending them. We immediately retired them to our lower paddock where they will happily devour the wild growth for a couple more months before moving on to their next venue.

Bad Sheep: A Blessing in disguise
The itchy sheep turned out to be a blessing, as Ruben came up with a better, even less intrusive weed management idea while in Burgundy. Since planting them, we’ve been grappling with how to effectively weed our new high-density vineyards where our tractors won’t fit. The vines are young and will need more water than our established vineyards, but they will also need sunlight currently being blocked by the wild growth. The crew pulled the more stubborn growth (namely Mustard) out of the new blocks mid-winter and after even more rain, the ground is still saturated with water. Next, once the weeds begin to dry a bit, La Cuadrilla will simply flatten the weeds sideways to create a seal for the moisture below.
We continue to watch the forecast – Ruben hopes for just one more storm front and then the 2017 growing season will be off to the races!