From the high lawns above the Vanderbilt overlook you can watch the Hudson ice up in slow plates, and that is Hyde Park's signal that the plow trucks are about to start their season. Lehan's Lawn and Landscaping Inc. runs both halves of the year — plowing, shoveling, walkway clearing and salting through the cold months, then mowing, trimming, edging and cleanups once the ground finally lets go in April. Late March here is mud and green shoots at the same time, and the first cut of the year is the one the whole street notices. Two seasons, one standard: the driveway open early, the lawn striped even, the edges honest. Steady work, in a town that has always kept its grounds.