Port Washington runs out onto its neck of land with Manhasset Bay on one side and the old sand banks rising behind, and the water shows up at the end of half the streets in town. Green Gene's Inc. works both halves of the calendar here: mowing, edging and yard care through the growing season, then plowing and salting when the harbor wind turns raw. Salt air is hard on a lawn, so the upkeep has to stay steady rather than occasional. Winter storms come in wet off the Sound and set up fast. The measure of a good day is a lawn with crisp lines in July and a driveway down to bare pavement in January.