A patch of green, brown or yellow moss is a cluster of small plants that appear in lawns located in shady and humid conditions. Moss takes hold of areas where grass grows poorly, forming smooth or hard mats on the bare soil. While it does not kill or damage grass, moss signals that your lawn is not planted under ideal conditions. Nourish your grass and treat any pest problems to get rid of the moss. For a quick fix, a little bleach helps.
Rake the area of your lawn covered with moss.
Mix 1 gallon of bleach with 1 gallon of water in a garden sprayer.
Spray the bleach solution on the moss. Expect the blades of mature grass to die and later regrow from the roots. Newly planted grass, however, could die completely and require reseeding.