Hastings-on-Hudson climbs straight up off the river, and the Old Croton Aqueduct trail runs level across all that slope like a green shelf laid into the hill. Desouza Landscaping mows and tends the yards on those pitched lots — cutting, trimming, edging, mulch and bed care on ground that seldom offers flat footing. A terraced lawn above Warburton takes twice the walking and shows every inch you skip, so nothing gets skipped. In June the late light comes back off the Hudson and lands sideways on the hillside, and it finds every line. A hedge squared, a lawn striped down the fall line — that is what the evening reveals.