Moss growth on lawns typically occurs in bare, moist and heavily shaded areas of the yard. While moss doesn't pose any risks of killing surrounding grass or plants, it does hurt the appearance of a lawn. Fortunately, moss problems can usually be permanently taken care of in as little as a week. A simple solution is to simply pull the moss away from the ground and over-seed the bare soil.
Apply an herbicide to the moss. Read the label on the package to ensure the herbicide is effective against moss. The moss should die within a day or two of the application.
Remove the dead moss from the ground with a garden rake. Moss roots are generally close to the surface of the soil, so it should be easy to rake it up. Discard the moss in a trash bag.
Cover the soil with a thin layer of grass seed. It's best to use more grass seed than necessary to ensure the growth takes over any moss that tries to grow back.
Sprinkle a ¼ inch layer of potting soil over the grass seeds. Do not use more than ¼ inch of soil as the seeds need to be close to the surface to germinate.
Water the soil so it is thoroughly moist. Keep it moist until the grass begins to grow. Treat the new grass as you do the rest of your lawn once it reaches 2 inches tall.