April in Parsippany-Troy Hills sounds like water finding its way back into the pipes. New Image Lawn Sprinklers LLC opens the systems for the season — valves on, heads raised, each zone walked and watched, spray arcs trimmed back off the sidewalk so the water lands where the grass is. Through the summer it turns to repairs: the cracked head a mower found, the zone that quit, the timer that needs to learn a new schedule. Then October, the compressor, and every line blown clear before the ground locks up. Between those two ends of the season the lawn itself gets tended, and the difference shows in a dry August.