If this bothers you, you should be aware that the reason the moss took hold in the lawn is because the soil has gradually become acidic. There is a tendency for most soils to become acidic. Grass clippings, leaves and twigs decaying in the soil help make it more acidic.
Lawn food applications and acidic rain also contribute. As the soil becomes acidic, it is harder for the grass to survive. As the grass (which prefers neutral soil) thins, the moss (which loves acidic soil) starts to take over. So how do we stop this vicious cycle? The answer is testing the soil’s pH and applying the amount of lime required to bring the pH of the soil back to neutral. Keeping the pH of the soil of your lawn at neutral (7.0) is, perhaps, the most important aspect of lawn care and, undoubtedly, the most overlooked. Besides discouraging moss, lime provides calcium and allows your lawn to make maximum use of any nutrients available. If you want to think of your lawn as a gasoline engine then lawn food would be the gasoline that makes the engine run. Lime would be the engine oil that makes sure all goes smoothly. Without oil, no amount of gasoline can make an engine run for too long. Without lime, eventually the lawn won’t grow as well as it used to. Think of your soil pH test as the dipstick you need to determine you’re how low your lawn’s pH is.
These pH test kits are cheap and easy to use and, believe me, can save you a lot of time and money that you’ll spend on grass seed and fertilizer trying to repair a situation that could have been avoided. Lime won’t kill moss but it will prevent it. Once it’s there you’ll have to rake it all out, apply lime, grass seed and a starter fertilizer and spend your time watering the grass seed constantly until it is established. Rest assured, if you care about your lawn, a pH tester is a bargain, and lime is cheap compared to lawn food and grass seed.