A stream runs through Manhasset Valley Park that most drivers on Northern Boulevard have never noticed, and in early October the London planes above it go the color of paper. Peter Valenti Landscaping keeps the lawns in that neighborhood through afternoons like those, cutting as the growth slows, edging so the lines stay honest, trimming and lifting the leaves as they come down. One name on the truck door tends to mean the same eye on the yard every visit, which is how a lawn develops character instead of merely length. Autumn work is slower and more particular than summer work, and the yards show it. By the time the planes stand bare, everything underneath them is clean.