The Hopkinton Trails Committee and the Hopkinton Trails Club have created a monthly trail volunteer day on the first Saturday of each month from 9 a.m.-noon. The next workday is Sept. 7 at the Fruit Street Athletic Complex. Volunteers will remove invasive Japanese knotweed. Parking is available at the Fruit Street parking area, by the turf and grass fields. For more information, visit hopkintontrailsclub.com.