Summer storms find Ossining fast — the sky over the valley goes green-gray, twenty minutes of hard rain comes down the hillsides, and by evening the back yards are steaming and everything has grown an inch. Those terraced back lots, stacked one above the next, are where JR. Landscape & Service Corp does its steadiest work: mowing, trimming, edging, mulching and clearing out what the weather knocks loose. Timing matters as much as effort here, because a lawn cut too wet is a lawn you can see your mistakes in for a week. Getting it right means a yard that looks calm the day after the storm. Ossining and the nearby Westchester towns make up the round.