Route 114 runs the length of Middleton like a spine, and Conway Landscaping knows it at every hour — the four a.m. dark, the noon glare off the farm fields, the long amber of an August evening. Summer here is mowing weather: grass that comes roaring back two days after a thunderstorm climbs up from the southwest, edges cut clean along driveway after driveway between the Danvers line and the North Andover line. Come January the same road goes white, and the work turns to plowing, walkways and salt laid down before the first commuter backs out. There is a particular satisfaction in a driveway opened while the house is still asleep, the apron squared off neatly at the curb. Middleton keeps early hours, and so does this outfit.