Washington
Wine News
Winter Worries "It" is a devasting winter freeze that occurs in Washington wine country every six years or so. The last was in early 1996, and growers and winemakers know they're due for another. Sara Spayd, a food scientist for Washington State University in Prosser, has been studying the phenomenon since she arrived in the Yakima Valley in 1980. "Mother Nature reminds us every five to seven years why we grow riesling," she says with a wry smile. Riesling, a white wine grape upon which the Washington wine industry built its reputation in the '60s and '70s, has been spurned in the past decade for more fashionable varieties, such as chardonnay, merlot and syrah. Unfortunately, these three varieties are more susceptible to bad winters, as shown in 1996 when Washington's merlot crop was less than a third of normal because of the freeze. This phenomenon that growers, winemakers and consumers alike are concerned with is not just about cold temperatures; it's all about how and when it occurs. For instance, in late January 1996, temperatures rose to a balmy 55 degrees Fahrenheit in many areas of the Columbia Valley, then plunged to minus-18 by Feb. 3. When the temperature went up, the vines "awoke" from their winter slumber and rehydrated the wood. And when temperatures dropped 75 degrees in such a short period, the water in the wood froze and expanded, damaging the vines' trunks and buds, often destroying everything above the soil. To make matters worse in '96, snow on the ground reflected the bright sun during the day and warmed the vines. When the sun set and temperatures plummeted again, damage to the vines' trunks was even greater. "Location is Everything" Some areas were hit worse than others. From Zillah in the western Yakima Valley to Walla Walla in the east, chardonnay and merlot vines were generally devastated. Yet south over the Horse Heaven Hills, little damage was noted because a heavy fog regulated the temperature. "If you're in an area prone to extremes, the potential for damage is much greater," Spayd says. Location is everything, she emphasizes. Vineyard sites with good slope and elevation tend to survive better when harsh winters occur. Someone who knows about bad winter freezes is Mike Sauer, owner of Red Willow Vineyards in the western Yakima Valley. His first experience was in 1971, when he was working with Concord grapes, two years before he began growing wine grapes. Since then, he can recall a half-dozen devastating winters. Sauer wasn't badly hit in 1996, with the only casualties some merlot vines in marginal locations. "There's no substitute for a good site," Sauer echoes. Sauer has had especially good luck with syrah, a darling among red wine consumers but a somewhat tender variety. Red Willow Vineyard had the first commercial planting of syrah in Washington in 1986 on a steep slope that is less affected by cold winters. Methods to Reduce Damage Sauer and other growers have learned a number of ways to lessen the damage when winter freezes threaten the wine industry. In addition to site selection, growers also will use fall irrigation to their advantage. Sauer wants his vineyards nice and wet going into winter because moist soil acts as insulation for a vine's root system. This is especially significant in 2001 because of season-long drought conditions. While a lack of water didn't seem to affect growers through harvest, many irrigation systems shut down earlier, leaving those dependent on late-fall watering - literally - high and dry. A devastating winter could cause more damage. Another method is piling up soil around the grapevines' trunks, which can protect a few more inches in case of prolonged freezing temperatures. This, however, is labor-intensive and difficult. Some growers take advantage of wind machines, which can mix the air, and therefore its temperature, as well as keep it moving. Spring Frosts Can Also Hurt Vines The devastation can take place in many forms, says Kevin Corliss, director of viticulture for Stimson Lane Vineyards & Estates, the Northwest's largest wine producer. In addition to freezes like the one in '96 that destroyed vines back to the ground, fall and spring frosts can damage buds. A vine's buds, which eventually flower and become grape clusters, are formed around June of the previous year. So the buds for the 1996 vintage were formed in 1995. If those buds are injured or killed, they can't become grapes. This is vital to Stimson Lane, which owns such wineries as Columbia Crest, Chateau Ste. Michelle, Snoqualmie Vineyards and Northstar. It owns or has contracts for 15,700 acres in Washington, more than half of the state's vineyards. Winter 78-79- A Bad One Corliss, who grew up in the Yakima Valley and works at Stimson's facility in Grandview, has lived through a number of freezes since he started working for the company after high school in 1983. And the Washington State University graduate has heard plenty of stories about the past, one of the worst being the notorious 1978-79 winter. On Christmas Day 1978, temperatures in the Columbia Valley reached the mid-50s, then plummeted 60 degrees in five days. It stayed cold for more than a month, hitting a high of 32 degrees only three times until Feb. 4. As a result, the ground froze 8-9 inches deep. Such a deep freeze will destroy anything in its path. "Kill the roots and you're pretty much done," Corliss says. "You get the opportunity to change varieties." For Stimson Lane, that winter was especially devastating. U.S. Tobacco had purchased Ste. Michelle Vintners in the early '70s, soon after Cold Creek Vineyard was planted. The '78-79 winter killed most of the vineyard because the vines were planted too shallow, about six inches deep. "Back in the old days, we took our planting methods right out of the California book," Corliss says. "We didn't worry too much about freezes and frosts." Fortunately, U.S. Tobacco didn't blink at replanting the vineyard - this time much deeper - and today, Chateau Ste. Michelle's Cold Creek Vineyard wines are among the most prized in Washington. Phylloxera another Potential Problem In 1996, Stimson Lane ended up with only about 40 percent of its crop because of that winter's freeze. And it would have lost more if its vineyards along Canoe Ridge and Columbia Crest facing the Columbia River hadn't been relatively protected by foggy and breezy conditions. The company also was generous to the rest of the region. Then-President Allen Shoup wanted to make sure the Washington wine industry wasn't wiped out, so Stimson helped smaller producers by selling them grapes. The experts point out that even when terrible winter damage occurs, the industry is able to bounce back quickly, usually by the next season. One of the main reasons for this is that, unlike many other wine regions of the world, Washington grapevines are planted on their own roots rather than grafted onto rootstock. A century ago, a little bug known as phylloxera gobbled its way across Europe, devastating three-fourths of the continent's vineyards. The solution was to graft the classic European grapevines onto American grapevine roots, which were resistant to phylloxera. Today, phylloxera continues to plague grape growers, particularly in California and, to a small extent, in Oregon. But Washington has an advantage. Its soils tend to be sandy, which phylloxera doesn't like. And the industry is young, spread out and doesn't have large farming companies that move their equipment around, a practice that can spread the louse. Because of its relative youth, Washington's wine industry grew up under quarantine conditions, thus making it more difficult for unwanted pests to make their way here.
As a result, nearly all Washington vineyards are not grafted onto rootstock but are "own-rooted." This helps in two ways. When a devastating freeze does happen, vines grafted on rootstock tend to sustain greater damage. And when own-rooted vines are knocked back to the ground, they can be retrained the same year and produce grapes the next vintage. If they were grafted onto non-European roots, the vines wouldn't produce the intended variety but whatever grape the root was from. Corliss keeps a close eye, too, on how different varieties do during bad winters. "Riesling is tremendously tough," he says. "We can always count on a regular crop of riesling." So is cabernet franc, a red wine grape often blended with merlot or cabernet sauvignon. "It's a hedge against winter. In a year like '96, you have cab franc." While it's well known that chardonnay and merlot did poorly in '96, cabernet sauvignon also can be susceptible, especially if the freeze is earlier, such as November. Grenache, a tasty though less popular red wine grape, is one of the most tender, Corliss says, though Stimson still gets plenty of fruit from vines planted in 1978. And syrah? That's a big question mark because many of the plantings have occurred since the last bad winter. "The jury's still out on syrah," Corliss says. "It hasn't been tested. But if it's sensitive, we'll find out and have to deal with it." And that's what Washington's grape growers and winemakers do. They know going in that the Columbia Valley is not always a wine grape growers' paradise. Every six years or so, they can count on it. ANDY PERDUE is editor of Wine Press Northwest.
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Washington Winter Weather Cycles and the Washington Low Temperatures may Distress Crops
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