Salt Brook runs low and cool through New Providence in August, and the lawns that follow its ground stay green a week longer than the ones up the hill. Certified Green Thumb LLC works both kinds — the damp bottoms and the dry, sun-hammered slopes — cutting, edging and clearing so each yard gets what it actually needs. Humid mornings here bring grass up fast, and there is satisfaction in arriving on the day it wants cutting rather than the day after. By evening the stripes lie flat, the beds carry a defined line, and the walk is swept bare. It is a quiet result, but it is the one homeowners see first from the driveway.