The Old Croton Aqueduct runs like a green seam down through Greenburgh, and the yards that back onto it catch their light early, while the grass is still cool. Alcantar Landscaping Inc keeps that hour — mowers warming, the first straight line laid across ground that tilts gently toward the Hudson. Mowing, trimming, bed edging and the cleanups that carry a property from thaw to the last leaf: plain to name, exacting to do. The satisfaction is in the final pass, when the edge along a walkway comes up crisp enough to read from the street. Hartsdale, Ardsley, Elmsford — the same clean line, yard after yard.