In late June, when the heat settles over Brockton's old shoe-factory brick and the maples along its triple-decker streets pool their shade on the sidewalks, Perez Landscape is already out with the mowers running. This is lawn care in a mill-town valley — the Salisbury Plain grass cut clean, the edges drawn sharp against the walk, the trimming worked close along fence lines and foundations until a yard looks like it has been listened to. Come October, they gather the leaves that drift down from the big oaks near D.W. Field Park and leave the grass breathing again before the cold. Across Brockton and the towns that ring it, the work is plain and physical and satisfying to stand back from: a lawn held to its season, block by block.