To get the most out of your lawn, you need to know what kind of grass you have and its needs: how much water, resistance to pests, tolerance to shade, amount of nutrients needed. If you’re starting from scratch, do some research to identify the best grass type for your climate and soil type. If you have an established lawn that isn’t all it should be, consider replanting with a more suitable type.
Next, test your soil. Inexpensive soil pH testing kits are available, or you can use litmus paper. Have your soil’s fertility tested by your state's cooperative extension service or a commercial soil-testing lab. Your local nursery can make recommendations based on the test results.
Most homeowners water too often with too little water. The key is to water thoroughly and only when needed, when the grass begins to wilt, the color dulls and footprints stay compressed for more than a few seconds. Drip hoses are the most efficient method. The next best thing is an in-ground automatic sprinkler system. To evaluate how long sprinklers should run, turn them on and time how long it takes for the water to penetrate four inches into the soil (open up the ground periodically with a shovel). Water only in early morning or evening.
For best health, mow frequently, but frequent mowing makes grass require more water. Sharpen your mower’s blades frequently to get a clean cut, and never mow when the grass is wet. Cut no more than 1/3 of the grass’s length at a time. Leaving your lawn slightly long will produce healthier, more pest-resistant grass.
One good reason to aerate your soil every year is that it helps to clear out thatch, the dead, undecayed material at the soil line. This material adds to a number of lawn problems. Before aerating, be sure to give your lawn a good, hard raking to loosen up and remove the thatch.
The best fertilizers are organic, slow-release types. Your soil's test results will indicate specific organic fertilizer recommendations. Although you can spread fertilizers by hand, you'll get more uniform coverage with a spreader (drop or broadcast type). Make two passes at opposite angles. Water thoroughly after applying fertilizer or apply it before an expected rain, unless the directions state otherwise.
Finally, use herbicides and pesticides responsibly. Follow package directions to the letter. Apply weed-killers when they first start to grow, before they go to seed. Apply these products with a hose-end sprayer or with a garden spreader.