Moss growth in place of grass is a sign of poor soil conditions. These include lack of sunlight, poor soil drainage or poor turf health. According to Oregon State University, moss growth is a sign that something is wrong and the condition must be corrected. If you take restorative action, grass can replace moss in these areas.
Prune overhead tree limbs, using a pruning saw. Remove limbs in such a way to cast sunlight pockets on the soil. Light reaching the ground will begin to deter moss growth.
Run a lawn aerator over the ground where the moss is growing. The lawn aerator will improve soil drainage. The soil plugs left on top of the ground will break down to mix the soil together.
Test the soil where the moss is growing. Collect samples from several areas of the lawn. Take the soil sample to your local agricultural extension service for analysis.
Spread the proper lawn fertilizer to the area based upon the soil test results. Follow the fertilizer packaging for application rates.
Broadcast a shaded-type grass seed over the moss area. Rake the seeds into the ground.
Irrigate the grass seed according to the seed package labeling with the garden hose and sprinkler. Do not overwater or allow puddles to form on the soil surface.