Six in the morning in Horseshoe Bend, and sprinklers are ticking across a hundred lawns at once while the sky over the Chattahoochee shifts from gray to gold. Green Grass Group Inc is already unloading. Fescue up in the shade, Bermuda out in the open sun — a single property can ask for two different cuts, and knowing which is which is most of the job. Mowing, edging, trimming and clearing the hard surfaces, week after week, is what keeps a summer lawn from getting away from the people who live on it. The routes run through Roswell and out toward Johns Creek, Alpharetta and Duluth.