Spy Pond thaws well before the calendar says spring, and the first mower you hear in Arlington is usually somewhere on the streets that run down toward its shore. Donato Bros mows, edges and trims those close-set yards, where a lawn might be twenty feet deep and every square foot of it is seen from the sidewalk. Small ground rewards precision — a straight edge along the walk, a clipped line at the fence, nothing left scattered on the brick. Spring cleanups pull the sand and grit of a city winter out of the beds, and autumn cleanups take the leaves before they pack down. It is neighborhood work at a neighborhood's pace, house after house down the block.