There are several reasons why mosses can be a problem in lawns. One or more of these conditions can allow mosses to compete with and overcrowd turf.
Control Try to physically correct the causes of moss. Remove limbs to increase sunlight and air circulation. Change grading or add drainage to allow water to drain away quicker. Core aerations will also improve drainage. Sometime evergreen needles will increase soil acidity; rake and remove the needles. Horticultural limestone can help to counteract acidity and raise the pH. Raise the mowing height to 3" to allow the lawn to compete better against the mosses.
Turf King can apply a moss control in the early spring or fall. This will kill the moss and turn it dark. The application also contains needed potassium and nitrogen. As the moss discolours, rake it up and discard it. This area should be renovated by overseeding. It is important to remember that moss control will kill the moss but will not change the conditions that caused the moss to proliferate in the first place.