Stone walls edge the dooryards in Amherst, half-sunk in leaf litter, and the roads climb slowly toward the long blue shoulder of the Holyoke Range. Boyden & Perron Inc keeps lawns here — the mowing and trimming, the seasonal cleanups that hand a yard back to itself in April and settle it again in November — and when the valley goes white, the work turns to plowing driveways and clearing the walks before the first car door opens. There's a plain satisfaction in it: a lawn striped and cooling in the evening light, snow pushed clean to the wall line, a path someone can cross without thinking about it. Between mud season and the deep freeze, a Pioneer Valley yard asks a great deal, and this is the work that answers.