University of Maine Cooperative Extension 4-H is offering its on-farm summer learning series for ages 12-18 starting 9 a.m. to noon July 15 at Rustic Roots Farm, 120 Vipah Lane Farmington. This is the second year “4-H Fridays on the Farm” has been offered for Maine teens to gain hands-on experience, talk with local growers and learn more about the Maine food system.