The Quinnipiac takes its time through North Haven, laying down the flat, sandy loam that made this town farm country long before it was neighborhoods. Green Thumb Lawn Care works that ground — mowing, trimming, edging, and the spring and autumn cleanups that keep a yard from going ragged at the corners. Summer here is humid and generous; grass grows fast between the river meadows and the Route 5 ridge, and staying ahead of it is most of the job. On a July evening, when the heat finally lets go and the mown rows run straight to the property line, a North Haven yard looks exactly the way its owner pictured it.