When the cherries along the Mill River greenway open, the whole downtown seems to lean toward the water for a couple of weeks. Landscaping U.S.A works the lawns in that stretch of Stamford and out through the neighborhoods around it — mowing on a regular beat, edging drives and walks, trimming what the mower leaves behind, mulching beds, and putting down fertilizer and seed to thicken whatever foot traffic wears down. Spring cleanups get the winter out of a yard; autumn cleanups get the leaves off before they compact. A short cut in June and a clean edge along the walk make a modest lawn look composed. That is the whole trade, done attentively, week after week.