Mine Falls holds the Nashua River in a long green pocket right through the middle of the city, and on a July evening the canal path smells like cut grass for a mile. La Croix Brothers Lawn Care works those late hours when the heat breaks — mowing, trimming, edging, keeping neighborhoods on either side of the water looking cared for. Grass in this valley grows fast off the river damp, so the schedule matters as much as the machine; a lawn kept on time never has to be rescued. Spring cleanup opens the season and autumn leaf work closes it, bookends on a long stretch of green. Two brothers' worth of pride goes into a yard that looks finished from the street.