One of the biggest secrets to having a lush green lawn lies underneath: soil with the proper pH. Getting the proper pH for the soil in your lawn is really more important than the seed. That’s because when you have the proper pH, your fertilizer works better. It lasts longer and you get much healthier grass.

Consumer Reports evaluated six home soil-test kits designed to measure the pH level. A pH scale consists of numbers from 0 to 14, with 7 being neutral. Lawns require a pH of approximately 6.5 to 7.

Testers took dozens of samples at seven different locations. They also sent soil samples to two outside laboratories to confirm the soil pH. Those results were then compared with the home test kits. Unfortunately, the home kits weren’t all that accurate. So they’re not the best choice for determining your soil pH. Instead, Consumer Reports says you can have testing done by your local cooperative extension, try a private lab, or ask a lawn-care service.

Soil in the Northeast and Midwest almost always tends to be acidic. And the correction for that is to use lime. The best lime to use is the pelletized version, which is easier to handle and it also lasts longer.

Soil in many parts west of the Mississippi and in Florida tends to be alkaline. To solve that problem, you’ll need to put down sulfur, or its equivalent, to get your soil to the proper pH.

Soil tests also indicate what mix of fertilizer you’ll need. When you fertilize is critical to effectiveness. In the north, fertilize your lawn once in the late spring and once or twice more from late summer into the fall. Make the last application right before your final mow of the year. In the south, you should fertilize your lawn in the spring after it turns green and then again in July or August.