Moss is a simple plant with no rooting system that grows in a dense mat. Moss is not a competitive plant, so when you see patches of moss growing in your lawn, it is often an indicator of something that is wrong with your lawn. The best method to get rid of moss in your lawn is to boost your lawn's health and vigor. A vigorous lawn will soon crowd out mossy patches.
Dig a soil sample from your lawn by scooping up a teaspoon of dirt from the surface. Then dig down approximately 3 inches and take another teaspoon full. Place both of these soil samples into a clean food storage container and take them to a laboratory that specializes in soil analysis. The soil analysis will tell you what minerals your lawn is deficient in.
Rent a dethatching machine and an aerator from a lawn supply store or heavy equipment store to remove thatch from your lawn and aerate the soil. Thatch buildup, a condition in which a lawn's roots grow back on itself, is a frequent contributor to moss. A poorly aerated lawn contributes to both thatch and moss.
Dethatch your lawn and remove moss with the dethatching machine. A dethatching machine operates much like a lawn mower in that you set the level with which the grass is removed with a lever and then push the machine over the lawn to remove thatch in layered strips.
Aerate your soil with the soil aerator. A soil aerator also operates much like a lawn mower in that you use a lever to set the depth to which the machine will remove plugs of dirt from your lawn. Then you push the machine over the lawn in sections.
Top dress soil with a nitrogen-rich fertilizer, compost and the minerals specified in step 1 by distributing these materials evenly over the lawn to a depth of 2 inches with a shovel.
Work soil amendments through your grass and down to the depths of the soil by combing the grass with a leaf rake.
Water lawn thoroughly to wash amendments into the aeration holes.