On summer evenings at First Encounter Beach the tide goes out for what looks like a mile and the whole bay turns the color of the sky — and behind the dunes, Eastham's yards are being kept in shape for the season. Js Landscape Inc. handles that upkeep: mowing, trimming, edging and cleanups through the warm months, then plowing and hand-clearing once the Cape empties out and the storms have the roads to themselves. Grass on the Outer Cape is a negotiation with sand and salt air, so consistency counts for more than ambition. A property that looks cared for when the family pulls in on a Friday in July is the whole job, and it is a good one. Eastham and its neighbors, from Orleans up to Wellfleet.