Issue link: http://read.dmtmag.com/i/61297
Grapes Options for when it's time to replant W Identify why a vineyard needs replanting before planning how to do it. by Melissa Hansen ine grape vineyards are replanted for a host of reasons—to change varieties, replace diseased or winter-damaged vines, and change trellis systems or vine spacings. When it's time for vineyard reestablishment, what are the options, challenges, and economics of replanting? The recent spate of vineyard replanting in Washington State is not unprecedented, says Jim McFerran, director of viticulture for Milbrandt Vineyards in Mattawa. Vineyards of Chenin Blanc and Semillon varieties were removed in the 1980s and replaced with potentially higher-valued varieties of Cabernet Sauvignon, Merlot, and Chardonnay. In the 1990s, replanting was due to winter freezes (1991 and 1996) that caused widespread damage and vine death, and grapevine leafroll disease in Pinot Noir and Lemberger varieties. But lately, interest in replanting has resulted from a culmination of factors, McFerran said. "A lot of vineyards are now 25 to 30 years old. We're beginning to see the seri- ousness of leafroll virus hitting Cabernet Sauvignon vine- yards, and to a lesser degree, Merlot and Chardonnay, and many of these same vineyards have been through five or six major freeze events in their life and are in decline." McFerran discussed his vineyard reestablishment experiences at Milbrandt Vineyards, owned by brothers Butch and Jerry Milbrandt, and the company's approach during a session on vineyard reestablishment that was part of the annual meeting of the Washington Association of Wine Grape Growers in February. In 2007, Milbrandt Vineyards purchased an existing vineyard on the Wahluke Slope. The 130-acre vineyard was planted to 17 varieties in 35 blocks, with many blocks less than four acres in size. "We knew we'd be challenged with the block design and multitude of varieties," McFerran said. "At Milbrandt, we already have about 200 acres that look exactly like that, and we cater those vineyards and blocks toward the boutique market." The first step in deciding if or how the vineyard should be changed was to determine where the grapes would go—to the custom crush Wahluke Wine Company for bulk wine, Milbrandt Vineyards wines, or high-end, boutique wineries. McFerran said they considered the following in regards to the newly purchased vineyard: • isolated location (access is by canal road, 30 minutes from central operations) • timing of vineyard tasks and harvest relative to already-owned vineyards • operating expenses (remote location increases operating expenses) • level of attention to detail that can be given in such a remote location • labor demands and supervision • potential wine quality and yield • potential revenue of site • site and variety suitability (hot, windy site) • age of vines, productivity, and severity of leafroll disease • existing vine row width and length (row widths were two feet wider and row lengths shorter than standard spacing in other Milbrandt vineyards) • marketability of vineyard to boutique wineries 36 APRIL 15, 2012 GOOD FRUIT GROWER A burn pile is all that's left of this wine grape vineyard that will be replanted in the spring. INSET: With the trellis left in place, the root systems of these young vines are in the process of being pulled out. "When we considered all these things, we ultimately decided there was opportunity for change," McFerran said, adding that the company believed the vineyard would best suit the wines of Milbrandt Vineyards and the Wahluke Wine Company. "If we set those targets, we believed that we could manage the vineyard to the best of our ability." Changes were made in the vineyard that would lead to better management—removing some rows and roads, lengthening row distances, expanding block sizes, remov- ing some varieties and planting others. The vineyard went from 35 blocks to 14 and from 17 varieties down to 8. Vari- eties now grown are primarily Cabernet Sauvignon, Petit Verdot, and Merlot. "We wanted to farm the parcel in a professional man- ner," he said. "We're glad that we made all these changes, though we ask ourselves why did we spend as much money on the changes as we did for the property. It might not make a lot of sense, but it's an awesome site, and some of our very best wines come from this vineyard." Replant decisions Once the reason "why" a vineyard should be replanted is identified, the "how" can be decided, said Dean Desser- ault, vineyard manager for Hogue Ranches in Prosser. "Once you decide if you're removing only plants, trellis and plants, or trellis, plants, and irrigation system, then you can plan the how." If the replanting reason is to change a variety that doesn't fit the current market or is not the right variety for the site, Desserault said growers may or may not want to leave the existing trellis and irrigation system in place. "If the plants were healthy and the soil healthy, but vines were just the wrong variety, at Hogue we might leave the trellis in place. If the plants coming out are unhealthy, but the soil is healthy, again, we might leave the trellis in place." But if any soil work needs to be done, such as fumiga- tion or ripping, he usually removes the trellis system. And if the trellis system needs repair and upgrading, or vine spacing needs changing, the trellis goes. Removal options It's possible to remove the plants and leave the trellis in place, though he admits the task is much easier if the vines are young. With young vines, the cordon wire is cut free from the vines, loppers are used to chop down the vines and trunks, and roots are pulled out and placed in the middle of the rows for flailing and mulching. "But older, larger vines are more difficult," Desserault said. Plants are cut down below the cordon wire and pulled out, then the cordon wire is cut and removed, along with loose posts, and other wires. Removing both plants and the trellis system is a more complicated process. Wire must be removed (leave the cordon wire in until trellis stakes are pulled out), wood and/or steel stakes and posts pulled out, and anchor posts removed. Vines are then removed and pushed into piles for burning later. A root lifter is run through the vine- yard to bring any broken crowns and roots up to the surface. "We like to do our vineyard removals in the fall so the burn piles can dry out, and then we get a permit and do our burning in the spring," he said. Wire is collected from the burn piles and removed from the vineyard. Desserault noted that grafting over a vineyard is an option if the soil health and trellis system are sound. "We've done this a little bit—with varying results—but it is an option." • www.goodfruit.com photo by Rick hamman