North Weymouth gets the salt. Off Wessagusset the wind comes in over the flats and lays a fine brine on everything, and grass growing a few streets from the water learns to live with it. Flagstone Landscape LLC handles those lawns — mowing, trimming, edging, spring cleanups and the long leaf work of fall — with an eye on how coastal ground drains and dries. A shore lawn will never behave like an inland one, and the trick is to stop fighting it and work with what the sand and wind allow. Kept right, it comes up thick and green with the bay air moving across it, which is a fine thing to look at from a porch step.