Vashon Winery is gearing up to present its third annual folk festival this weekend — an outdoor event on the winery grounds that will expand this year to fill two days with workshops, panel discussions and performances by some of Vashon’s most beloved traditional, Celtic and contemporary acoustic musicians.

The festival is being helmed by Mark Wells, Chuck Roehm and Deirdre Grace. The trio has invited more than 15 acts to take the stage — an event organizers hope will be a crowd-pleaser for all kinds of audience members as well as aspiring musicians.

“There will be plenty of open mic opportunities,” Grace said, adding that the event was also meant to appeal to families and lovers of acoustic music. “Bring your picnic basket and your guitar.”

Vashon Winery has expansive grounds, and performances will take place in the winery’s orchard, in the shade of a grove of apple trees. During the winery’s first festival, the location proved to be an idyllic spot to listen to music, winery owner Ron Irvine said.

“It was a hot year that year, and as we sat listening, apples were dropping out of the trees,” he laughed.

For Irvine, it is exciting to see the folk festival blossom and grow — doubling in scope from one day of music to two.

The winemaker has long hosted literary and musical events on the grounds of his small winery; he was also been one of the forces behind the 2009 Vashon Poetry Fest and this year’s ReadOn WriteOn VashOn, a festival of books.

Wells, Roehm and Grace, he said, have brought a lot of energy to planning the folk festival. “As a group, they just wanted to see this thing become bigger, and I didn’t have a problem with that,” he said.

Saturday’s lineup includes RiverBend, Kate Graves, Steve Amsden, Andy James and a group of students from Chautauqua Elementary School, Rose Laughlin, Wally Bell, Cat Loves Crow, Allison Shirk and Mark Wells. The headline performance on Saturday evening will be by Kat Eggleston and Kate Macleod. After their performance, there will be a campfire and barbecue.

On Saturday afternoon, there will also be a tribute to Bob Woodman, a former Islander who founded a long-running jam session in his garage next door to Vashon Winery. The jams grew into a band, The Garage Boys, well-remembered by longtime Islanders.

Woodman, who recently moved to Port Orchard, will be present at the tribute, along with some of his family members.

On Sunday, the day will begin with workshops by Mark Graham, Orville Johnson and Sarah Christine and include performances by Christine, The Diggers, Kelsey Alina and Jeff Kanzler. It will end with a headline performance by Orville Johnson and Mark Graham.

The Vashon Winery Folk Festival will take place from 10 a.m. to 10 p.m. Saturday, Aug. 21, and 10 a.m. to 5 p.m. Sunday, Aug. 22, at Vashon Winery, 10317 S.W. 156th St. Tickets, sold at the door, are $15 per day or $20 for both days. Children under 16 are free; students will receive a discount. Workshops cost extra. Wine, hard cider, non-alcoholic beverages and food prepared by Island chef Paul Motoyoshi will be sold. Vashon’s Ranch Hostel will provide discounted camping and teepee accommodations. For more information, visit the Vashon Winery Folk Festival page on Facebook or visit www.myspace.com/vashonwineryfolkfestival.