The Concord River bends slow and brown through Billerica, and the light coming off it at six in the morning is the light this crew works by. Summer means mowing lines laid straight across river-flat yards, edges cut clean where turf meets walk, clippings gone before the heat comes up. Come January the same trucks are out ahead of the school buses, pushing driveways open while the streetlights are still doing all the work. There is a particular satisfaction in an apron cleared at five in the morning: black pavement, banked snow, a house that can simply leave. All Seasons Landscaping keeps both halves of the year in hand for Billerica and the towns around it.