Choose the Right Grasses
Focus on mixtures of grasses adapted to your region. A mix of grasses ensures that a disease problem won't affect every blade of turf in your lawn. And focus on your conditions: Almost all grasses prefer full sun, but a few, including fine fescues, tolerate some shade.
Remember that sometimes, the best grass is no grass -- and using ground covers or planting beds makes the most sense.
Don't Cut Your Lawn Too Short
Tall grass is usually healthier grass. It grows longer roots, which access more water and nutrients. And because it has more leaf area, tall grass is also more vigorous than closely mowed grass. The taller leaves also shade out weeds. Most grasses grow best when kept at least 2 inches tall.
Hint: No matter what height you let your grass grow, remove no more than one-third of the grass blade in a single mowing. Removing too much at one time causes stress.
Keep a Sharp Lawn-Mower Blade
A dull lawn mower blade tears grass instead of cutting it, resulting in frayed grass that's susceptible to disease. Sharpen mower blades at least once at the beginning of the season. Sharpen again during the season if your grass looks ragged after you mow.
Leave Clippings on Your Lawn
Clippings left on the lawn decompose and add nitrogen and organic matter to the soil. (Plus, you don't have to rake as often.) Contrary to popular belief, clippings do not contribute to thatch buildup.
Note: Use a mulching mower to finely mince blades, so they decompose and benefit your soil more quickly.
Thatch is an impenetrable mat made of grass blades, roots, and rhizomes that forms over the soil. A thick layer of thatch prevents water from reaching roots, and serves as a welcome mat for disease and insect pests. If thatch isn't severe, aeration may solve the problem. Thick thatch requires a vertical mower or mechanical dethatchers to break it up.
If your ground is hard, if it has dry spots where grass fails to grow, or if you can't poke a pencil 4-6 inches into a moist lawn, it needs aeration. Aeration improves drainage, breaks up thatch, stimulates lawn growth, and improves lawn health -- all without pesticides or fertilizers. Aerate when the lawn is actively growing (spring or fall for cool-season lawns; summer for warm-season lawns).
Water your lawn when grass takes on a dull green or bluish color, when leaf blades begin to fold or roll, or when footprints remain in the grass after you've walked on it. Water deeply and infrequently: You want roots to grow deep into the soil -- healthy roots extend 6 inches deep or more. Consider weekly rainfall before setting out the sprinkler. Water based on the weather rather than your weekly planner.
Watch for Weeds
The best thing about healthy, organic lawns is that they naturally defeat most weeds without help from you. If your lawn has weeds, it may indicate a different problem. Use organic products, such as corn gluten meal (CGM) when necessary.
Feed Your Lawn
Use a balanced, natural fertilizer to feed your lawn. Most natural fertilizers are slow-acting, remain available over time in the soil, and rarely damage the lawn by burning grass.
Apply fertilizer once or twice each year. Be careful not to use too much: Even natural fertilizers can damage plants when used in extreme. Always follow the instructions on the fertilizer packaging. With fertilizers, less is better!
Top Dress with Compost
Compost works miracles in the soil for gardens and lawns. Spread up to a quarter of an inch of compost over your entire lawn each spring or fall.