Todd Newhouse of Washington’s Outlook Vineyards and Upland Winery says they first experimented with grape grafting about seven years ago on a whim, without any need for changing varieties.
"We tried a row just to see what would happen, not really having any plans to graft," Newhouse said, noting that the small trial was a success. "But then three years later, starting in 2005 and 2006, we found ourselves in a situation where we had a big need for grafting. So, we used our experience to change seventy acres."
At the time, there was little grape experience to draw from as few grape growers were grafting in Washington, he said. But the gamble paid off. "We had dang near one hundred percent success in our grafting take."
More recently, they grafted another 30 acres, with the same margin of success.
Newhouse said that they usually graft in April, using a professional grafting crew from California. They use the side graft method, cutting trunks off and training the grafted scion wood up to the wire.
"We miss the current crop year but have full production by the next year that can even be mechanically harvested," he said.
Outlook Vineyards is located in Washington State’s newest American Viticultural Area called Snipes Mountain. Washington’s tenth AVA, which encompasses about 4,150 acres and was approved in February, is actually one of the state’s oldest growing regions, with grapes first planted in 1914 and 1917. The Newhouse family is now reestablishing the Upland Winery, which operated from 1934 to 1972.
Snipes Mountain provides a unique microclimate that has resulted in very little injury from winter temperatures, a consideration when grafting. He acknowledged that growers are leery of grafting because of worry about winter injury. "But in most parts of the Yakima Valley, you don’t really lose whole vines to winter injury."
Newhouse stressed that growers need to make sure they use clean scion wood that is free of diseases like grapevine leafroll virus, testing it if necessary. They also choose wood from young vines they know were clean and were planted within the last few years to help ensure that diseases haven’t moved in. "You need to make sure the wood is clean from crown gall."
Switching back and forth
The biggest advantage to grape grafting is that it gives growers more varietal options without the time and expense of replanting.
For instance, they had an abundance of Cabernet Franc and grafted the variety to Pinot Gris. He tells that after grafting, they wanted to supply smaller wineries with more Cab Franc than they originally planned, so they switched back to the Cab Franc. They took one acre that had been grafted to Pinot Gris and trained the new Pinot Gris to the bottom wire, then took a sucker from the Cab Franc trunk and trained it to the top wire, reverting the vines back to the Cab Franc.
"We cut off the Cab Franc in the first year, and had no crop while we trained the Pinot Gris to the wire," he said. "The next year we had a Pinot Gris crop, while training the Cab Franc suckers up to the alternate wire. The following year we cut off the Pinot Gris cordon and kept the Cab Franc.
"In all this, we only lost a year of production. Grafting gives you the option of going back to the original variety if things change. It can be done," Newhouse said.