The Pawtuxet River comes down through Warwick past old mill stone and back yards, and the ground along it stays green well into the fall. Twin Roots Landscaping works both ends of the year — mowing, trimming, edging and leaf cleanup while the grass keeps at it, plowing and spreading salt once the river runs cold. From Cowesett to Buttonwoods the lots change character every few streets, and the equipment has to change with them. What does not change is the finish: an even cut and a border cut true in July, a plowed driveway with no ridge left at the apron in February. Two seasons, one standard.