Spring comes up the Connecticut early, and the South End greens before the hills do — small front yards, church lawns, strips of grass between the sidewalk and the street. Olivera Landscaping works that ground: mowing, trimming, edging, and the cleanups that clear a winter's worth of grit out of the beds. Down by the riverwalk the April wind still carries a chill, but the grass does not wait for permission. Keeping a narrow city lawn sharp takes more hand-work than a wide-open one, and it shows from across the street when it is done. Week by week through the season, block by block.