Downtown Brooklyn is mostly pavement and glass, which makes every patch of grass in it count for double. CitiLawn tends those patches — the strip beside an entrance, the lawn in a building courtyard, the green edge of a plaza under towers reaching toward the bridges. Cutting, edging, weeding and cleanup, all of it on a schedule so nothing ever gets ahead of itself. Downtown grass is looked at by thousands of people a day and it ought to look like somebody is paying attention. Grass cutting and grounds upkeep in Brooklyn.