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The current boundary of the Puget Sound AVA, shown in the yellow outline, excludes a sizable area that’s suitable for wine grape production, based on average annual growing degree-days that fall within 1800 to 2400. years, and the Pacific Decadal Oscillation, lasting from 40 to 60 years. Jones said, in short, it means a low risk of weather extremes for the Puget Sound, but high climate variability. Climate trends As part of the research, Jones looked at both 30-year Puget Sound climate averages Vineyard/Orchard Weed Control See for yourself at: WonderWeeder.com from 1971 to 2000, averages from 2000 to 2008, and climate trends from western United States wine grape production regions (eastern Washington, Oregon, and California). He pointed out that temperatures in the 1950s and 1960s were quite cold, and even from 1971 to 2000, there were only a few areas in the Puget Sound that had adequate heat units for wine grapes. Warming trends in more recent years have increased the nighttime temperatures and increased the number of frost-free days in Puget Sound, he said. Many areas have low risk of frost, with 180-plus days of frost-free growing. In comparing weather data from 1948 to 2008, based on five nonurban Puget Sound weather stations, Jones found the number of spring frosts had declined 12 days, and overall temperatures were getting slightly warmer. The number of ripening days from August 15 to October 15 that were above 95°F were trending upward, but not statistically significant. He explained that the warmer temperatures are primarily a reflection of higher nighttime temperatures and not significantly higher maximum or daytime temperatures. Overall precipitation has not changed much in the western United States. Rain is mostly a concern for wine grapes during bloom and harvest. He found no real difference in winter precipitation in the region, but there was a trend for slightly more precipitation during bloom, though not during the ripening or harvest period. While rain during bloom could be a concern, he said there are many isolated and pro- tected zones with a rain shadow effect within Puget Sound. “There are some very dry zones in the area,” he said, adding that he knows of a Sequim grower who has kept records for 15 years and reports an average of 12.5 inches of rain annually. One thing that Jones observed during the project was that the current Puget Sound Cut or Eliminate Your Chemical Weeding Costs! AVA boundaries miss a majority of the area he identified as suitable for wine grapes. “It doesn’t include most of the area that’s suitable,” he said. Many of the warmer sites in the area—located on intermediate slopes of the foothills, isolated hillsides, up inner-sound river valleys, and over protected zones on islands—are not included in the AVA. And while Jones’s terroir modeling provides suitability insights, he noted that his research focused primarily on the North Olympic Peninsula, and needs to be done over a broader area of Puget Sound to identify the best zones for planting. Solid potential “I think there’s solid potential for cool-climate viticulture in this area,” Jones said, comparing the climate structure of Puget Sound to Germany’s Mosel Valley and Tasma- nia. “Thirty to forty years ago, I wouldn’t have said that, but today, I think a lot of poten- tial is there for great development for the wine industry in Washington. The region benefits from its proximity to a large market, and it should capitalize on the ability to grow unique grapes with a light, crisp, and aromatic style that pairs well with the seafood of the region.” He believes that the Puget Sound AVA should be expanded to include other areas that 509.539.1725 36 JUNE 2011 GOOD FRUIT GROWER are climatically suitable for wine grape production. Of more than 135 AVAs in the coun- try that Jones has looked at, most need to be redefined. “A lot of the AVAs were approved in the mid-1980s, established on frameworks that were not physically based but based on things like railroad lines, rivers and streams, and not climate, topography, and soil.” Jones gave his talk at the annual meeting of the Washington Association of Wine Grape Growers. • www.goodfruit.com