With three decades of experience, growers are making better decisions, says a Washington State viticulturist
Washington State's wine grape industry has learned much in the last 30 years of growing vinifera grapes. As second-generation vineyards are now being planted, growers are making changes with regard to matching the variety and site, clonal and variety diversification, and vineyard configuration.
When Washington growers began planting wine grapes in the late 1970s and early 1980s, little information was known about which varieties would do best in specific locations. The late Dr. Walter Clore, Washington State University horticulturist, laid the groundwork for growing premium quality vinifera grapes, but his variety trials were just a start for the burgeoning industry that would eventually plant vineyards to all borders of the state.
Growers replanting and expanding into new areas are using technology to better site and lay out their vineyards. Weather stations are recording temperatures and charting degree days, Global Positioning Systems (GPS) are being used to map vineyards, and growers are analyzing soil variations within a location.
With new technology and the experiences shared by industry pioneers, growers are making more intelligent planting decisions, said Kevin Corliss, director of vineyard operations for Ste. Michelle Wine Estates. In the past, warm and cool varieties were planted side by side, with little understanding of what grows well where, he said. "We planted using a big shotgun effect because we didn't know any better."
Variety and site
One of the biggest areas of change—matching varieties to specific sites—has taken the longest to learn, Corliss said, adding that it takes years for a vineyard to come into production, settle down, and provide meaningful yield and fruit quality data.
"There's more focus now on planting the site according to variety without compromising the cleanliness of the planting material," he said. "At our Cold Creek Vineyard and in Canoe Ridge Estates near Paterson, we planted red and white varieties like Riesling, Cabernet Sauvignon, and Merlot, side by side. In the early years, some growers thought their site was a warm location if apricots or peaches could be grown nearby."
Nowadays, private and WSU weather stations provide long-term temperature data. Experience has taught the industry that 3,000 heat units are needed to ripen Cabernet, and that Riesling can be planted on cooler elevations of 1,500 feet.
"It's been a planting evolution through education," Corliss observed, adding they've learned Sauvignon Blanc isn't fit for the warm Cold Creek site, but that Cabernet thrives there in the hot, stressed environment. At Canoe Ridge Estates, they now know the steep, south-facing slopes are best suited for Merlot and Chardonnay, while Syrah and Grenache do well in the vineyard's rocky sites, where hearty Rhone varieties thrive.
Cold Creek Vineyard, located about 40 miles east of Yakima and south of the Columbia River, was planted in 1973 and is one of the oldest sites in the state. It comprises nearly 730 acres of Cabernet, Chardonnay, Merlot, Riesling, Syrah, Cabernet Franc, and Grenache, which go into single vineyard or Ethos tier wines for Ste. Michelle.
The story about clonal and variety selection for Washington is just beginning to be told as feedback on some clones starts to filter through the industry. Although formal research on clones has not been conducted in the state, many growers have been planting different clones under trial in the last decade to learn which ones do best. With many clones already in the ground, it's just a matter of time before fruit, yield, and wine quality evaluations are analyzed.
Clones are about giving winemakers choices when blending, Corliss said. Initially, growers focused on clonal selections for Merlot and Cabernet. Merlot clones 15 and 6 have become popular selections in Washington due to experiences shared by growers and wineries. However, in recent years, Ste. Michelle and others have been trying clones of Chardonnay, Riesling, Syrah, and Petit Verdot. At Canoe Ridge Estate, three new clones of Merlot and four clones of Cabernet were recently added; more than 25 different clonal selections are under trial at various Ste. Michelle vineyards.
"But cloneliness is not next to godliness," Corliss said, explaining that growers are better off planting nothing than planting suspect or "dirty" material that has not been tested for virus.
"Finding clonal material to plant has been slow going because clean plant material was not always available," he said. "In the past, there was a good source of Cabernet clone 8, but not a lot of other selections."
An expansion of varieties has also taken place in Washington State. For example, growers have increased acreage of varieties like Malbec, Cinsault, Mourvédre, Petit Verdot, and Cabernet Franc that are used in blending by winemakers to create different wine styles.
Corliss believes that in the third generation of vineyard planting, even more clonal and variety refinement will take place.
Vineyard spacing is one of the main differences between older and newer vineyards. In the 1980s, the standard in Washington was ten feet between rows and six feet between vines. Growers tightened up the alley width to nine feet in the 1990s. More recently, alleys are even narrower, with widths of seven and eight feet, and three, four, and five feet between vines.
The move to higher densities is driven by the need to maintain economic yields without adding more crop per vine. Corliss said that higher density gives growers the ability to keep yields at economically viable levels, yet at the same time, gives them more flexibility in terms of yield.
He noted that at Ste. Michelle's new Col Solare planting on Red Mountain, vine spacing is on a seven- by three-foot spacing. "I'm not sure we would do that again, but the spacing was something that the venture partners were accustomed to in Italy. The more vines you plant, the more expensive it is."
At Cold Creek Vineyard, new plantings are spaced eight by five feet apart. "They're not making any more Cold Creek land," he said.
Corliss said that at both Cold Creek and Canoe Ridge vineyards, they are pursuing sustainability and are in the process of being certified by LIVE (Low Input Viticulture and Enology), a nonprofit, third party that offers certification through the International Organization for Biological Control.