On summer mornings the Kennebec sends fog up over Richmond, and it burns off right about the time the mowers start. Pine Tree Lawn Services keeps yards through the green season — cutting, trimming, edging and the cleanups that bracket it at both ends — then turns to snow plowing, shoveled walks and sand on the ice once the river runs slush. Pines drop needles all year in this town, so a lawn asks for tending even when it isn't growing much. There is a particular satisfaction in a yard finished just as the last of the fog lifts off the water. Come January, the same satisfaction arrives at first light with a driveway already open.