By July the bermuda and zoysia across north Fulton are running hard, and the crabgrass is running harder. GrassRoots Turf keeps to the treatment calendar that decides which one wins — fertilization, pre-emergent and weed control, attention to insects and disease, aeration when a summer of foot traffic has packed the soil tight. It is quiet work, mostly invisible, until one morning in the right week the whole lawn has changed color evenly, corner to corner. Alpharetta soil is stingy until it is fed and generous afterward. That turn is what the whole schedule is built around.