Lawn moss is a common issue in grass that is not taken care of with the correct practices. Soil that is not appropriate for grass will commonly show indications of lawn moss, a threadlike green plant that grows throughout bare patches in the grass. Moss prevents nutrients from reaching the soil, which further reduces the ability for grass to grow.
Acidic soil, those with a pH reading of 7.0 or lower, will reduce the ability of grass to properly cover the lawn, says the North West Coalition for Alternatives to Pesticides. A lawn that is not fully covered with grass will have increased moss growth. Acidic soils require improvement with lime. Lime increases a soil's alkalinity, balancing out the acidity. Although changing the acidity of a soil does not kill moss, it reduces its occurrence.
Shady areas that do not receive enough sunlight to properly dry the soil are more prone to moss growth. Tree branches or other obstructions require removal if possible to increase sun coverage, says the Virginia Cooperative Extension. If removal is not possible, a shade-resistant variety of grass will increase turf coverage and reduce the growth of moss.
Compacted soil will increase the growth of moss due to its inability to drain properly. Compaction requires aeration, says the Montana State University Extension Service. Aeration removes 3- to 4-inch plugs of dirt from the lawn, increasing drainage and air circulation throughout the soil. A handheld tool with hollow tines is available for the aeration of a small area of grass, but large aeration machines are available that remove the plugs at greater speed.
Proper fertilization of the soil prevents the growth of moss as it increases the grass coverage over the lawn area. Fertilization twice a season at one pound of nitrogen per 1,000 square feet of surface area will increase grass coverage. A soil pH test will determine your lawn's exact needs. Any existing moss on the lawn requires removal with a rake.
Proper Mowing Practice
Proper mowing practices increase grass turf coverage and prevent weakening of the grass. Most grass requires a mowing height of between 2.5 and 3 inches to reduce sun burning. When mowing the lawn, only one-third of the grass blade should be removed at a time to reduce injury to the grass blade and to reduce the soil's thatch content.