Farmers State Bank will be entering the Johnson County market next year with a branch in Tiffin.The Marion-based bank has announced plans to build a full-service office on a one- to five-acre lot at 1600 N. Park Rd. in the Park Place and the Ders Group development. Construction will begin in spring of 2020, with a projected fall opening.“Tiffin is one of the fastest-growing communities in Johnson County and probably all of Eastern Iowa,” said Gene Neighbor, president and CEO of Farmers State Bank.