April along Sea Street smells like thawed ground and low tide in the same breath, and every yard in Snug Harbor is holding a winter's worth of sand, salt and broken twigs. Medeiros and Sons opens the season there: raking the lawns out, clearing the beds, laying mulch, cutting the edges back to a line and taking the first mow of the year. That first cut is the one people notice — the grass suddenly greener for having been touched, the driveway swept, the street looking like the year has properly started. From then on it is steady mowing and trimming through to fall. Spring in this part of Quincy is short and abrupt, so the crew moves with it.