Hopkinton keeps its old field walls out in the woods — walk the state park trails and you find stone lines running through pine, still holding the shape of farms nobody remembers. Green Vistas Landscaping LLC tends the open ground on the other side of those walls: mowing week to week, trimming the edges, cutting borders along beds and paths, mulching, and hauling the leaves off in fall. August dries the high spots to straw while the hollows stay green, so one yard can want two kinds of attention. A property looks its best when the mowed lines run true and the borders are honest. That is the whole ambition, week after week.