A struggling Denver lawn usually tells you what is wrong long before anyone digs. Lawn M.D. reads those signs across Hilltop, Crestmoor and Montclair — the south-facing strip scorched by afternoon glare, the compacted clay where nothing will root, the pale patch that means feeding rather than watering. The treatment follows: aeration to open the ground, fertilization on a schedule the season actually calls for, overseeding into the thin places, weed control before the dandelions set seed, and mowing and edging to keep the whole thing looking intentional. Grass at 5,280 feet lives under harder sun and drier air than the back of the fertilizer bag assumes. Work with that instead of against it and a lawn holds its color straight through the dog days.