By mid-July the salt haze drifts in off Quincy Bay, and the grass along Quincy's granite-shouldered streets grows back faster than anyone can keep it low — which is where the long days of M.O'donnell Landscaping Co. begin. In a city quarried from stone and shadowed to the west by the Blue Hills, the crews work yard to yard with mowers and edgers, coaxing a striped, unhurried order out of every dooryard and slope. There is a plain satisfaction in the result: the trimmed line where lawn meets sidewalk, the clippings raked away, a green that keeps its color from the Wollaston beach blocks out toward Merrymount. When the maples let go in October, the same hands come back with rakes and blowers to carry the season off the grass and leave the ground ready to rest. It is lawn work measured in the settled look of a Quincy yard put right.