IF YOU LIKE YOUR LAWN CRUNCHY, NOT SMOOTH, then this is your moment (or at least it is if you live in my neighborhood). A 10-foot-wide patch of frost settled on the grass beside the patio overnight, and though it didn’t nip at much else, its message was clear: We have plans for you, Margaret, and they don’t include sunbathing and fresh-picked tomatoes. How’s the weather over there?