On a July evening off Washington Avenue in Endicott, the light goes long and yellow between the houses and the whole block smells like cut grass. Trevett Lawncare makes that smell. Mowing, trimming, edging — the plain vocabulary of a good yard, repeated week after week until a lawn holds its shape on its own. By dusk the fireflies come up out of grass finally short enough to see them over. It is small work, and it changes a street.