David Fisher has been weed free for nearly 15 years.

With eight acres of organic vegetables, Mr. Fisher has developed a system of crop rotation at his Natural Roots Farm and CSA in Conway that has kept weeds to a bare minimum. Mr. Fisher will speak about his technique on Friday night at the Martha’s Vineyard Agricultural Hall to kick off the Living Local Harvest Festival this weekend. The sixth annual event highlights all things sustainable, from vegetables to animals and energy to shellfish, and all in an effort to welcome the harvest and rejuvenate Vineyard for fall.

Mr. Fisher’s talk begins at 7 p.m., Sept. 28, with festivities continuing on Saturday at the fair grounds from 10 a.m. to 3 p.m.

Between cover cropping, soil management and stale bedding (leaving a field unplanted and lightly tilled when new weeds germinate), the fields at Nature Roots are pristine.

“With whatever practices people are doing, they have to suss out how effective it is relative to your goals,” Mr. Fisher said this week. “One of our primary goals is weed control and that’s something we do fairly well out... weed pressure is not a major issue.”

Nature Roots is explicitly horse-powered. For anything that usually requires a tractor, two Belgians are used in its stead.

“If it requires more muscle than we can muster ourselves – tillage, managing cover crops, plowing, bed forming, cultivating, transplanting, some harvesting, haying – we do it with horsepower,” he said. “And in the winter time we’re logging... we really enjoy getting creative using horse power wherever we can.”

The festival on Saturday will include a family drum workshop held by Rick Bausman, a local and wild food “culinary adventure” with D’etente chef Kevin Crowell, a slow food cooking demonstration with Cathy Walters focused on tomatoes, and a fish filleting demonstration with fishmonger Warren Doty.

A series of speaking events will also take place inside the hall. Island Grown Initiative will present an update on the proposed plan for an Island slaughterhouse with Cleveland Farm owner Richard Andre, there will be a backyard chicken talk with the chicken man himself, Jefferson Munroe of the Good Farm, and things may get a bit stinky in the compost area as prize-winning composters share their tips. Jan Buhrman of Kitchen Porch Catering will also be holding a “lacto-fermenting” demonstration. Homemade kimchi or kombucha anyone?

And don’t forget the food. 7a Foods is on for breakfast, Chilmark Coffee will be serving hot and cold coffee through out day, Chris Fischer of Beetlebung Farm is dishing up fish tacos and vegetable sandwiches, Morning Glory Farm will have burgers and hot soup. Eat on a hay bale while you’re serenaded by Good Night Louise while watching pumpkins sail through the air as Morning Glory launches them from their medieval style trebuchet.

An afternoon nap may be in order before the evening’s potluck. Bring a dish, a friend, a bottle of wine and your own cups and place settings. Not to fear if you come empty handed — donate $10 per person or $30 for a family of four and you can eat like a king. Afterwards work off the feast at a contra dance led by The Flying Elbows; musicians not dancers, that is.

— Remy Tumin