Winter in the northern hemisphere is usually a quiet time in the vineyards. But for producers who work in some of the coolest winegrowing areas, such as the Finger Lakes region of upstate New York, winter brings a whole new set of challenges, namely, keeping a vineyard alive through sometimes harsh weather conditions.
The biggest danger to vines during the winter months comes from large and sudden temperature swings before the vines have gone fully dormant or have had a chance to acclimate. The Finger Lakes region dealt with a severe and sudden cold snap during the winter of 2004, when many growers lost from 10 to 25 percent of their vines. Even though losing a few vines every year to winter kill is a fact of life in the Finger Lakes, those are some eye-opening numbers that vintners don't want to see repeated.
So, with a serious cold snap forecast for the next few days, I checked in with a few of the area’s top winemakers to see what they were expecting.
“Actually, I think we're in pretty good shape,” said David Whiting of Red Newt Cellars, located on the eastern shore of Seneca Lake. “The forecast for the next few days is for highs of 5° to 10° F and 0° to 5°-below at night. We've had some persistently chilly weather lately [so] the fluctuation over the next few days is forecast to be minimal. The vines should be pretty well-acclimated.”
“As long as we stay above 0° F, we will be fine," said Morten Hallgren, owner and winemaker at Ravines Wine Cellars. "The vines are in full dormancy now, so this is the best time for the Alberta clipper to glide by, [a fast-moving low-pressure storm that sweep across the area, bringing drastically lower temperatures]. We have about 12 inches of snow cover, which greatly helps as an insulating blanket. This is especially true for my newly planted vines on Keuka Lake.” (Younger vines with less trunk wood are far more susceptible to harsh winter conditions than older vines with more established trunks.)
In addition to snow cover, growers can also insulate their vines by a process called "hilling up": "We plow up a mound of soil about 12 inches high around the base of the vine each fall which protects the graft union and some basal buds," said Frederick Frank of Keuka Lake's Dr. Konstantin Frank winery. "Soil provides excellent insulation, which ensures the base of the vine will be protected regardless of how cold the air temperatures get. This ensures that we will not have to replace the vine because the basal buds under the soil will be protected and will provide canes to replace a damaged trunk if necessary."
In addition to cold temperatures, the wind itself also plays a factor in how the vines make it through winter. The wind chill reading your weatherman gives you is just as important for the vines.
"Wind chill does effect how quickly buds lose their stored heat," explained Peter Bell, winemaker at Fox Run, located on the northwestern side of Seneca Lake.
Luckily for the vines, the lakes themselves have a moderating effect on the area's climate. Because they are so deep, they never freeze. Ice that does form on top of the lakes eventually sinks, bringing up (relatively) warmer water from below. Air flow off this then acts as a protective barrier for the vineyards that are along the lake shores. Problems arise when the air flow goes still, or if it rolls in from the east instead of the prevailing west (which is what happened in 2004). Vineyards at higher elevations, where the protection of the lakes is less evident, are also in danger, though most of these vineyards in the Finger Lakes are planted with hybrid and native American grapes that don't generally go into serious wine production.
Riesling, the area's best variety, is among the hardiest vines, along with Cabernet Franc and Chardonnay. These vines can shrug off cold down to around -10° F. In contrast, Merlot and Gewürztraminer are among the wimpiest of vines, and temperatures below zero can cause them problems.
Hopefully the results after the dead of this winter will be as good as the outlook is now, and the area's vintners won't have to deal with too much winter kill going into next spring. And next time you’re snuggled up by the fire with a good glass of wine, just remember what those poor little vines have to go through.
David A Zajac — January 14, 2009 9:32pm ET
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