More Washington State growers are using grafting to make quick changes in their variety mix.
Rusty Figgins wraps the oblique side graft with tape. Right: The new graft after splicing, taping, and painting.
The practice of grafting to a different grape cultivar in Washington State, once considered very risky, is slowly taking hold in wine grape vineyards, though it's not done without careful consideration of location and vine health.
In early April, a small group of Pacific Northwest viticulturists learned the techniques of side grafting in a Mattawa, Washington, vineyard from viticultural consultant Berle "Rusty" Figgins, Jr., and tree fruit grafter Gary McMonagle.
In the past, other grafting workshops have also been sponsored by Washington State University.
At the Ginkgo Forest Vineyard in Mattawa, ninth-leaf Syrah vines were being transformed to Pinot Noir, using the oblique side graft. Scion wood of Pinot Noir, with two buds per stick, were cut, slipped, and taped into trunks of Syrah. Figgins said that what makes this grafting different from some methods is that only one of two cordons was removed from the Syrah vines.
He calls this "seamless grafting" because only one of the two bilateral cordons is cut, leaving half of the Syrah crop for this year. "Next year, the new variety of Pinot Noir will produce, and you can then cut off the other Syrah cordon."
Figgins notes that by ramping up production of the new variety over time, the grower is not left without a crop in any given year. "In this manner, you never have to sacrifice a crop. It may be limited, but you still have a crop."
The cordons that were removed, originally trained up as two trunks in the vineyard, were cut low to the ground about three weeks before grafting took place to allow time for the wood to be chopped, out of the workers' way during grafting.
The new cane of Pinot Noir will be trained up and arched as a unilateral Guyot system, he explained. The Guyot system, named after French scientist Jules Guyot, is essentially a cane pruning method using one or two canes and one or two spurs, with the canes trained in opposite directions along the wire. At the crown, two buds will be left in the renewal zone for next year's canes.
Figgins experimented with different pruning styles a few years ago while serving as viticultural consultant and winemaker at Cave B Estate Winery near George, Washington. From his pruning experiments, he found that the wine was better from cane-pruned vines than those that were spur-pruned.
"Certain varieties can have low-quality fruit from the basal bud positions of one and two," he said, adding that fruit from buds one and two will be different than fruit from buds six through eight. "You get a higher proportion of more fully formed fruit from the six through eight buds than the basal buds."
Though Figgins is a fan of the Guyot cane system, he said that most growers in Washington use spur pruning, a method that is easy to learn and works well for mechanized pruning. The Guyot system would not work for mechanical pruning because the pruner would indiscriminately cut the canes that are desired, he noted.
Grafting is a quick way to change varieties and is useful when you have an overabundance of a variety, Figgins said. But he pointed out that not all locations in Washington State are well suited for grafting. Areas that are hit hard by above-ground freeze damage in the winter are risky locations. Areas like Canoe Ridge, Rattlesnake Hills, the Columbia Gorge, Lake Chelan, Wahluke Slope, and vineyards near the Columbia River are more suited than some areas in the Walla Walla Valley or on Red Mountain.
"It doesn't mean that you can't graft there," he said, but there is greater risk if the vine dies and the grafted variety is then lost.
Figgins pointed out that if crown gall is present in the vineyard, it can cause problems, particularly if the graft union contacts the soil where the Agrobacterium thrives or the graft union is improperly sealed, allowing crown gall entry.
Steve Carberry, vineyard manager from Black Hills Estate Winery in Oliver, British Columbia, Canada, and Jesse Cooper, also of Black Hills, participated in the Mattawa workshop to learn how to graft by themselves. Black Hills recently grafted five acres of Pinot Noir to Cabernet Sauvignon, Merlot, and Semillon, using a grafting crew from California. But the small amount of acreage was not worth the hassle of bringing a crew across the border, Carberry said, which is why he would like to learn the skill. He has plans to graft three acres of Chardonnay to Carmenere and Semillon this year. Black Hills has an annual production of around 6,500 cases.
Other workshop attendees were from Mount Angel in Oregon, and Washington State.
There are a few bold Washington grape growers who have tried grafting in the last decade. Four years ago, the Good Fruit Grower published a story about work done by commercial grafter Ken Coates in another Mattawa vineyard owned by Greg Jones, along with grafting experiences shared by Ste. Michelle Wine Estates's Jerry DeCoto.
Though much of Coates's grape grafting work is done in California vineyards, he does some business in Washington vineyards. Of late, he's been doing a lot of grafting work in Oroville vineyards.
"There's a lot of interest by grape growers in grafting in the state," Coates said, admitting that he is still trying to perfect the timing for grafting in Washington's cool climate. "I'm not certain of the window yet."
Last year in Oroville, he had almost 100 percent take in one block, but only 50 percent success in another similar block in the same vineyard. While he usually grafts in March, Coates tested grafting in May this year to see if there were differences.
At Outlook Vineyards in Washington's new Snipes Mountain appellation, Todd Newhouse has successfully grafted about 100 acres of grapes in the last four years and has a small block planned for this year.
Though Figgins has done thousands of grafts on Australian vines, he's only grafted at two locations in Washington State. He believes more growers should consider grafting to change varieties instead of ripping out vines.