South Cape Beach sits where Waquoit Bay opens to the Sound, all dune grass and wind, and a few minutes inland that same salt air goes to work on ordinary Mashpee lawns. Mainely Grass tends those lawns — mowing, trimming, edging, and the spring and fall cleanups that largely decide how the rest of the year goes. Sandy ground drains before you can blink, so a Cape lawn stays green on attention rather than luck. The finish is the thing: clean margins, clippings cleared, a yard that looks composed from the road. Week to week, that is the whole errand.