Irondequoit Creek winds through Ellison Park under a canopy that keeps the valley cool while the rest of the county bakes. Masters Landscaping cuts lawns in the neighborhoods above it — mowing, edging, string trimming, and the cleanups that bookend the growing season. On a long August evening the light comes in low and sideways, and a freshly cut lawn holds its stripes like corduroy. That is the part worth doing carefully. Browncroft, Penfield, Brighton and the east-side streets are the regular circuit.