"Every lawn is different," says Kevin Morris, director of the federal Turfgrass Evaluation Program in Beltsville. "There's no cookbook, no recipe for growing grass." That said, here are some tips from him and other professionals:
* Test soil for fertility and acidity at least once a year.
* Despite Maryland's sultry climate, many professionals recommend planting cool-season grasses. This category includes bluegrasses, fescues and ryegrasses. Each of these has different tolerances for shade and foot traffic. For a lawn that receives a mix of sun and shade, a combination of different types of grass may work best.
* September is the best time to plant cool-season grasses. Warm-season grasses may be planted any time between May and September.
* With all the work involved in growing a good lawn, it pays to start with the best seed you can afford.
* Don't overwater. Grass is more likely to recover from drought than from flood, which can wash away nutrients and pesticides and promote the growth of fungus. Give the lawn one good soaking a week, 1 to 1 1/2 inches of water, rather than several light sprinklings a week, which promote the growth of a shallow root system.
* Aerate the soil at least once a season; this allows roots to breathe.
* Keep lawn mower blades sharp. Dull blades make a ragged cut, exposing a larger area of the grass plant to disease.
* Mow often, as the grass plant will be weakened if too much is removed at once. But keep grass height at the high end of lengths recommended for the different varieties.