In August the coolest thing in Middleton is the mist standing over Middleton Pond a little after five in the morning. Mike Fiore Landscp Irrigation Design likes lawns at that hour — dew silvering every blade, the day's heat still an hour out, the grass saying plainly where it is thriving and where it is going thin. Late-summer turf on this sandy Essex County ground wants a light touch: mowing high, clean trimming at the bed lines, cleanups that let air and water reach the roots instead of stalling in thatch. Read a lawn right in August and it holds green into September rather than going the color of straw. It is slow, watchful work, and anyone walking past on the sidewalk can see how it came out.