Saturday morning on the green near the Tuck Museum, the grass is short and bright and full of shadows from the maples along the edge. Banana Bins LLC brings that same cut-and-tidy standard to Hampton lawns: mowing, string trimming, edging, and carrying the season's clippings and leaves away. Yellow light, a mower running early, a yard that looks better at noon than it did at eight — it is a plain kind of good. Beds get their borders cut back so the mulch line holds a clean shape. Come autumn, the same yards get cleared down to bare turf before the ground hardens.