East Rochester runs right up against the Salmon Falls River, with Maine on the far bank and mill houses standing shoulder to shoulder on this one. Farris and Son Property Maintenance LLC mows those close-set yards, where a lawn might be twenty feet wide and still deserves a true edge. Late August the grass slows, the river runs low, and the work shifts toward trimming, cleanup and getting ahead of the leaves. Tight lots take patience — more hand trimming than mowing, more walking than horsepower. Done right, a row of small yards down a mill street looks like one long, well-kept green.