Fog rises off the Connecticut and lies over the Great Meadow most mornings in Charlestown, so the first mow of the day waits for sun to burn it clear. Prosperity Landscapes works those river-terrace yards — mowing, trimming, edging, mulching, and running spring and fall cleanups on the flat rich ground below the Fort at No. 4. It is old farmed land, generous to grass, and a lawn here will run away from you in a wet June if nobody keeps after it. Keeping after it is the job: a straight edge along the walk, beds squared, clippings gone before the truck pulls out. By afternoon the meadow is green all the way to the Vermont hills, and the yards along it look the way this valley deserves.