Mid-December’s below-freezing temperatures pushed grape vines into dormancy, and this month’s steady rains have increased groundwater supplies, helped leach salts from the soils and generally soaked the dry ground, viticulturists say.
Along with other Santa Barbara County residents, I have welcomed with open arms storm after storm this month, and winemakers and vineyard managers are beside themselves with glee — and have their fingers crossed in anticipation of a more average growth year.
That would be one fueled by winter rains and seasonably cold temperatures that push bud break back to its typical date of mid-March — spring.
During the prior three years, higher-than-average temperatures and little to no rain have tricked grape vines into sprouting new shoot growth as early as late January in some areas.
Viticulturists will tell you that the biggest risk of early bud break is a late-winter frost episode, one that kills green shoot growth and can decimate a vineyard overnight.
On Jan. 12, I spoke with Alison Thomson, owner/winemaker of Lompoc’s Lepiane Wines and vineyard manager/winemaker for Jalama Cañon Ranch wines, also in Lompoc. Our interview was well before last week’s spate of nearly back-to-back storms that soaked soils to the point of mudslides.
“The December freezes, combined with this month’s rains, are really going to help,” she emphasized. “Overall, cold and wet weather is a really good thing.”
Thomson emphasized how vital it is for vines to enter full winter dormancy — hibernation, if you will.
“This one is a more typical winter,” she said, because “for the last few years, it’s been so warm, not all vines have gone dormant. For the first time in three years, everything is dormant, which means the plants get a break. It’s good for them to be able to recharge their reserves.”
After at least three seasons of little rain and unseasonably warm winter temperatures, the grape vines get stressed, which in turn makes them less resilient and more susceptible to pests and afflictions such as Pierce’s disease.
That malady, often fatal to vines, “has rebounded during the past couple of years” because vines are thirsty and weak, Thomson told me.
Pierce’s disease is caused by the bacterium Xylella fastidiosa, which is spread by insects, the xylem-feeding leafhoppers known as sharpshooters.
Xylella fastidiosa acts by blocking the xylem, the plants’ vascular tissue that conducts water and dissolved nutrients upward from its roots, and helps to form the woody element in the stem of the vine.
In addition, a scarcity of water limits grape vines’ ability to flush out the salt that naturally builds up in a vineyard’s soil, Thomson said. “Salt toxicity is a serious issue, even in well water.”
January’s consistent rains have generally saturated soils and recharged groundwater supplies, she added.
On Jan. 19, I tracked down two other winemaker/vineyard managers via email.
Eric Mohseni, director of winemaking and vineyard operations at Zaca Mesa Winery & Vineyards north of Los Olivos, echoed Thomson’s enthusiasm for the wet winter weather.
“December’s nice cold weather shut the vines down and, so far, we have not had a warming trend to wake them up,” he wrote. Besides, cold weather is “great for pruning,” which typically takes place in January or early February.
Mohseni and Karen Steinwachs of Buttonwood Farm Winery & Vineyard in Solvang called the timing of recent rains especially beneficial as the moisture fueled the growth of vine rows’ cover crops.
I asked both Mohseni and Steinwachs, each in their respective positions for more than a decade, if they could recall such a good start to a rainy season.
“Doesn’t it seem like what we were promised last year we’re getting this year?” Steinwachs quipped.
In all seriousness, she wrote, “the last really rainy start I recall was 2005, although 2010 and 2011 had reasonable rainfall.”
However: “That’s just part of the equation — frost now is good. Frost at bud break is a disaster. Rain now, great! Rain at (grape) ripening, a calamity,” she wrote.
“I honestly don’t remember a January like this,” Mohseni wrote, adding that as of Jan. 18, Zaca Mesa had received 9 inches of rain. “There was the El Niño year of 1996/1997, but that was before my time here at Zaca.”
Steinwachs, the general manager and winemaker at Buttonwood, termed the cold and wet weather picture perfect.
“We got ground cover in just before the first rains, so got nice germination for that. And then we got the frosts, putting those vines to a well-deserved winter nap.”
Buttonwood is also a working organic farm, and “the frosts are also really good for the orchards and their dormancy needs,” Steinwachs noted.
— Laurie Jervis blogs about wine at www.centralcoastwinepress.com, tweets at @lauriejervis and can be reached via winecountrywriter@gmail.com. The opinions expressed are her own.