When the cherry esplanade at the Brooklyn Botanic Garden opens up, all of Prospect Heights seems to notice at once. Dragonetti Brothers Landscaping is out in that same stretch of spring getting yards ready — winter debris carried off, beds edged and mulched, the first cut taken off the lawn. Through summer it is mowing and trimming on a rhythm; by November it is leaves lifted off the grass before the cold presses them flat. Washington Avenue in the evening, a finished yard behind a wrought-iron gate: modest work, but you can see it from the street. Cleanups, mowing and yard care in Brooklyn.