Up in Silvermine the river runs shallow over ledge, the road bends along with it, and the lawns lie in and out of shade all day long. G.E. Landscaping LLC works that dappled north end of Norwalk — mowing, string trimming, edging along drives and stone borders, and spring and fall cleanups under trees that drop plenty. Shade grass is its own puzzle: cut it too low and it thins, cut it on time and it holds. In May, when the maples fill in and the mown lines run down toward the water, a whole street can look like it is being kept well.