Late August, up in the hills toward Byram Lake, the air goes heavy by four o'clock and the hickories start turning their leaves over. Jeovany's Tree Service watches that sky, because a Westchester thunderstorm on saturated ground can take a whole root plate with it. Cleanup out on those reservoir-country roads runs long: cutting a trunk off a stone wall, freeing a driveway, hauling until the place is a yard again. When the weather settles, the work goes back to trimming and pruning — thinning crowns so the next storm has less to grab — and to removing the trees already living on borrowed time. It is a good feeling to drive past somewhere you cleaned up and see that nobody could tell.