Late August in Leyden comes with crickets singing in the stone walls and a low amber light slanting across the fields toward the Green River. Landscape Interactions looks after lawns in this hill town just north of Greenfield, where houses sit far apart and every yard has its own view. Evenings cool quickly at this elevation, and grass tended through the heat of summer holds its color well into September. A kept lawn in Leyden is the small civilized square beside the barn, the woodpile and the open land. Landscape Interactions takes pride in keeping that square green, level and welcoming.