Warm temperatures reawaken Sonoma County vineyards (w/video)

Paradise Ridge winemaker Dan Barwick was tromping around a hillside vineyard that overlooks Santa Rosa in late January when he was startled to see tiny green leaves protruding from dozens of young pinot noir vines.

In the 17 years that the Dover, England, native has been with Paradise Ridge, he has never witnessed bud break this early in the growing season. Normally it doesn’t occur until March.

“I said, ‘Oh my goodness,’ and then, shall we say, something English,” Barwick recalled Wednesday.

Record-breaking heat on the North Coast in January and early February, including last Saturday’s scorcher of 80 degrees in Santa Rosa that obliterated the previous record for the date and tied the city with one in Texas as the hottest places in the 48 contiguous United States, has resulted in the unprecedented transformation of some vineyards.

“It looks like March already,” Barwick said Wednesday as he gestured across the hillside expanse of vines, blooming mustard plants and thriving cover crops.

The 17-acre organic vineyard is at the eastern edge of the Russian River Valley appellation and overlooks Santa Rosa’s Fountaingrove neighborhood. About 200 pinot vines that have shown early bud break are at the top of the ridge where they are bathed in sunlight. Barwick said a large oak tree growing near the vines probably increases ground level temperatures by trapping heat, further promoting growth.

But this much growth? In what supposedly is winter?

“We’ve replanted the whole vineyard in the last 10 years and never seen this before,” Barwick said.

Other grape growers reported imminent bud break in their vineyards, weeks and sometimes months ahead of schedule. It is a sign that spring is creeping into Wine Country, where Sonoma County’s 60,000 acres of vineyards are reawakening from their winter slumber.

Bud break signals the start of the 2015 grape-growing season, beginning a process that will culminate with harvest in the fall. The vines, which go into a state of dormancy over winter, begin to grow again when temperatures warm the soil. Sap resumes flowing in the vines, roots begin to absorb nutrients and buds swell from the wood, sprouting green leaves that will soon soak up energy from the sun and begin the process of photosynthesis.

“It’s ready to pop,” said P.W. Scoggins, winemaker at Karah Estate Vineyards east of Highway 101 in Cotati.

The images Scoggins and other winemakers have shared through social media have generated curiosity and concern. Early bud break could become a problem for growers if they then have to contend with killer frost this spring.

This time last year, grape growers were in a panic over dwindling water supplies and lingering drought. Growers packed meetings held up and down the North Coast to discuss their options and to trade tips for conserving water. Many took out crop insurance as a hedge against major crop loss.

It’s been a much different story this year. December’s pounding rainstorms filled most farm ponds and reservoirs, alleviating short-term concerns about water. Another warm Pacific storm was expected to arrive on the North Coast on Thursday and bring several more days of rain.

Barwick said a weekend storm would be perfectly timed to further bolster groundwater supplies and get vines through the early stages of the growing season. But frost remains a concern.

The buds will gradually shoot into leaves and vines and, finally, clusters of plump grapes. When temperatures fall below freezing, vineyard managers spray the tender buds with water to form a protective ice shield on the grapes. The frost protection season generally runs from March 15 to May 15.

On Wednesday, Ned Horton, vineyard manager at Quivira in Dry Creek Valley, moved portable wind machines into position as an early precaution against frost.

“Normally I’d be doing this several weeks later in the year,” Horton said.

The weekend rainstorms, which are being fueled by the Pineapple Express pattern, could slow growth in the vineyards, or even promote it, depending on how warm it is.

High temperatures in Santa Rosa during daytime are supposed to be in the 60s. Sunny days and warm temperatures are expected to follow the rain next week, according to the National Weather Service in Monterey.

A succession of warm, sunny days shattered records for three consecutive days last week. It began last Thursday, when Santa Rosa hit a high of 70, breaking the old record of 68 in 2007. Temperatures rose again Friday to a high of 73, breaking the previous record of 68 in 2013.

On Saturday, the city reached a high of 80 degrees, eclipsing the previous record of 68 degrees, set in 2009. That also tied Santa Rosa with the city of Edinburg, near the border of Texas and Mexico, as the hottest cities that day in the lower 48.

“Grapes don’t have a clock. They go by temperature,” said Doug McIlroy, director of winegrowing at Rodney Strong Wine Estates. “When the average temperature is above 50 degrees, they start to come out, regardless of what time it is.”

You can reach Staff Writer Derek Moore at 521-5336 or derek.moore@pressdemocrat.com. On Twitter @deadlinederek.