Due to questions about the environmental impact of various lawn-care chemicals, some homeowners prefer natural lawn care practices that do not use chemicals.

Although some people claim that these natural treatments are ineffective, others swear by them. And natural treatments are not just the province of do-it-yourselfers: plenty of professional lawn care services offer natural approaches as well. Even TruGreen ChemLawn, one of the big chemical treaters, has a pesticide-free program that features natural fertilizers.

Natural Soil Improvement

To improve the pH and nutrient levels of your soil via natural methods, try the following:

• Test the soil’s pH , then add the lime or sulfur that’s required to create a slightly acidic pH.
• Spread high-quality compost, in the form of a top dressing, over the lawn. Top dressing is made by combining compost with topsoil in a 60/40 mix. Spread the dressing across your lawn and rake it down to the roots of the grass. Then go over the lawn with a power aerator. The holes that the aerator creates will allow rainwater to carry the dressing deeper into the ground. Add top dressing at least once a year.
• Apply organic fertilizer to meet the nutrient needs indicated by your soil test. In the northern states, the best time to fertilize is late summer; in the southern states, the best time is mid-spring. Use slow-release products and spread them at the rate recommended on the package—the slow-release approach results in stronger plants.
• Make sure that your lawn has the right grass for your climate (see Types of Grass). If you don’t have the best grass for your area, you can overseed the lawn with a different grass variety for several years and eventually have a better lawn (see How to Overseed Your Lawn).

Natural Weed and Insect Control

The natural approach maintains that the best way to control weeds and insects is simply to have a healthy lawn: strong grass will drive out weeds and won’t support harmful insects as much as weak grass will. But for lawns that need a lot of help, there are herbicides and insecticides made from natural materials.

Corn gluten is a relatively new natural herbicide that can be very effective against crabgrass, dandelions, and other common garden weeds; it also fertilizes the soil. Biological insecticides and insecticidal soaps can also reduce insect populations significantly.

How to Apply a Top Dressing

To apply a top dressing of topsoil and compost:

1. Cut the grass low.
2. Combine compost and topsoil, in a 60/40 mix, in a wheelbarrow or garden cart.
3. Spread the top dressing in rows across the lawn. Apply 100 pounds of dressing per 1,000 square feet of lawn.
4. Use a garden rake to distribute the top dressing.