Bud break in Oakville

Chardonnay vineyards showing bud break in March the Oakville AVA.

Silverado Farming Company

The growing season has begun in Napa’s vineyards, with the first buds opening on vines from Carneros north to St. Helena. Over the coming weeks and months, shoots, leaves and berries will follow.

Caleb Mosley, senior viticulturist with Michael Wolf Vineyard Services, said Thursday that bud break is prevalent in the southern end of the county, citing a client’s blocks of chardonnay off Cuttings Wharf Road in the Carneros region.

“From what I’ve seen so far that’s where bud break is really taking off,” Mosley said.

Bud break of merlot and malbec had also been spotted in Rutherford, on the western side of the valley, Mosley said.

Brittany Pederson, viticulturist with Silverado Farming Company, said she had begun to see bud break of chardonnay in Oakville as early as last week. Pederson corroborated reports of Rutherford merlot and malbec and said bud break of petit verdot had also been spotted in the area.

Buds in blocks of sauvignon blanc in a Silverado Farming client’s vineyard near St. Helena had also begun to emerge, Pederson said.

A release from the Napa Valley Grapegrowers on Thursday put the amount of vines currently experiencing bud break at 15 to 20 percent and offered a glimpse of the process taking place as vines begin to stir.

“As temperatures warm and soil becomes drier, vines emerge from dormancy and begin to push water up from their root systems,” the release read. “Miniature buds on the vine, developed during the prior year, begin to swell eventually producing shoots from the bud. These shoots will then spring tiny leaves that help accelerate growth, especially as temperatures continue to increase.”

The arrival of bud break across the county is occurring almost two weeks behind last year’s first showing, Pederson said. “According to my historical data, we’re 10 days behind last year, which would put us back on track for a normal year.”

According to Mosley, bud break appears to have come “one or two days before the long-term average.” But “it’s feeling more like a normal start to the season at this point,” he said.

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As for cabernet sauvignon, both Pederson and Mosley said the vast majority of vines had yet to show bud break either in hillside vineyards or on the valley floor.

While predicting that cabernet sauvignon bud break would occur “in the next probably week or two,” Pederson noted, “It depends how long this warm weather holds out. That’ll be the driving factor for sure.”

The vines that have begun the growing cycle are meanwhile poised to benefit from the substantial rain received during the winter months, Mosley said.

“With the amount of water that’s in the root zone currently, what you end up seeing is a very even push of bud break … which is a really good thing because bud break dictates how the vine is going to continue growing throughout the year.”

Though buds are now exposed to the lingering threats of frost or additional rainfall as the wet winter dwindles, Napa Valley Grapegrowers Executive Director Jennifer Putnam said in the group’s release that growers are prepared.

“Growers are farmers and, in general, are ready to manage for quality in the face of whatever Mother Nature hands us,” Putnam said. “They are prepared to deal with weather events through technologies in the vineyard, and a very high level of know-how throughout our growing community. We are relieved to be past the drought years and are looking forward to a healthy growing season.”


Henry Lutz covers the local wine industry. He has been a reporter and copy editor for the Register since 2016.