There is a week in April when Marengo goes from straw to green almost overnight, and the whole town seems to sit up straighter for it. Yellow2green landscaping Inc works that turn — mowing once the ground is firm, pulling out the dead thatch, overseeding the thin corners where the plow banks sat all winter. A lawn is mostly patience: give it attention every week and by June it will not need rescuing. Out north on Route 23 the fields are only just starting, so the front yards in town get to be the first real green in the county. That is a fine thing to be responsible for.