Jackson Family Wines announced a deal Thursday to buy the sprawling Russian River Valley ranch owned by Saralee and Richard Kunde, who hosted some of the region's most popular fundraisers among their vineyards and helped raise millions of dollars for the agriculture community.

The 260-acre site off Slusser Road includes Richard's Grove and Saralee's Vineyard, where the Kundes planted grapes in 1988. Today, it has more than 200 acres of top-quality vineyards, including more than 50 clonal selections of grapes sold to 45 wineries.

"We've sourced grapes from this property for many years and know first-hand Saralee's and Richard's commitment to quality," Barbara Banke, chairman of Jackson Family Wines, said in a statement.

The sale is expected to close in early December. Financial terms were not disclosed.

"Richard and I are both very, very happy," Kunde said. "We've met with the whole (Jackson) family, and they have a lot of the same philosophies as far as sustainable winegrowing, and they, I think, will be very good stewards of the land."

The long-term contracts on the grapes also were sold, and Jackson Family Wines plans to honor those contracts, Kunde said. The Kundes kept about 80 acres of vineyards, and plan to continue selling grapes to 15 wineries, including Jackson Family Wines.

"We definitely don't want to be out of the grape-growing business," Kunde said. "I love it, and my husband does too. It's been a way of life."

When the couple bought the property, the five-acre grove was a mass of poison oak and blackberry brambles. Richard Kunde, a horticulturist inspired by Butchart Gardens in Victoria, British Columbia, transformed the area, planting hydrangeas and rhododendrons amid the oaks and redwoods.

Over the next two decades, the family turned the ranch into one of Sonoma County's best-known vineyards, both for the grapes they produced and the charity events they hosted.

About a year ago, after the 2011 harvest, the Jackson family approached the Kunde family about buying the property, Kunde said. The offer came as the Kunde family was ready to downsize, Saralee Kunde said.

The Kundes, dubbed "the first couple of Sonoma County agriculture" when they were inducted into the Sonoma County Business Hall of Fame last year, are widely respected for their roles as community benefactors.

Each year, they held more than a dozen events to raise money for ag interests including the Sonoma County Farm Bureau, Sonoma County 4-H Foundation and Future Farmers of America. Jackson Family Wines plans to continue that tradition, the company said in a statement.

"This site has long been an important venue for community gatherings," Banke said. "We will continue to honor the tradition of hosting events at Richard's Grove."

That commitment was critical, Kunde said.

"That's why we developed the grove to begin with, to do those charity auctions and offer the place for fundraisers," Kunde said. "That's been a big part of what we've done and who we are. They (the Jackson family) have been very philanthropic to the community, and they want it to stay that way, and to use the grove for those events."

The Farm Bureau held its "Love of the Land" fundraiser there every year, an event that drew about 900 guests, and helped provide scholarship and fund educational activities, said Lex McCorvey, the group's executive director.

"We in Sonoma County are so blessed that we've had the Kunde family's support and commitment," McCorvey said. "It's just unheard of. Their commitment to agriculture, and agricultural education, and enabling us to utilize that facility, has literally benefited thousands and thousands of kids."

Richard and Saralee Kunde are not affiliated with Kunde Estate Winery, the Sonoma Valley winery operated by Richard Kunde's niece and nephews.

You can reach Staff Writer Cathy Bussewitz at 521-5276 or cathy.bussewitz@pressdemocrat.com.