Bud break in Sonoma County vineyards began the first full week of March, a few days ahead of normal, says Nick Frey, president of the Sonoma County Winegrape Commission.
The first vines to unfurl leaves were early varieties like Chardonnay, Pinot Noir and Grenache.
Growers are starting this season with a little more spring in their step, as buyers have become more active and grape prices have strengthened.
“The market is definitely changing,” Frey says. “One- or two-year short-term contracts are being replaced with longer-term deals. There’s even some discussion of planting contracts, which can run for 5 to 10 years. The last time they were being offered in this area was 10 to 12 years ago.”
A cold winter, with nighttime thermometer readings consistently below freezing for long periods, could bode well for this year’s crop.
“Temperatures were cold enough for good dormancy,” Frey says. “That should result in a more uniform bud break and carry through to harvest, with less variation in grape maturity.”
Winter rainfall has been more plentiful in Sonoma County than in some of the state’s other grape growing areas. “Soil profiles aren’t at capacity, but there’s a fair amount of moisture in the ground,” he says.
Except for growers who have delayed pruning to lessen the threat of frost by gaining an extra week or so before bud break, pruning was completed by early March, Frey says. Following bud break, growers will begin spraying fungicides to prevent powdery mildew.
“It’s here every year, and worse some years than others. But, growers do a good job of controlling powdery mildew. Many use the UC Risk Assessment Index model to determine spray frequency. They stay on top of the disease to keep it pretty well suppressed, including last year when they were under a lot of powdery mildew pressure.”
Micronized sulfur and oil are popular tools for eliminating any early-season mildew growth.
A variety of cover crops are helping to control soil erosion on vineyard slopes. When incorporated into the soil, they add organic matter and, in the case of legumes, nitrogen. With normal winter rains, this vegetation helps dry out soils for proper vine root growth in the spring. However, with the fairly dry weather pattern this winter, preventing loss of soil moisture may trump that.
“In a year like this, water conservation will probably be a higher priority,” Frey says. “Growers will keep their cover crops short or disk them under to save water.”