Moss Control in Lawns
by Don Janssen, Extension Educator
Moss does not “crowd out” turfgrasses,
once it is established, grass plants will not
spread into mossy areas.
Moss is one of the most persistent and annoying weeds that occurs in home lawns. Basically, it is an opportunistic plant that will grow where turfgrasses are thin and weak. Moss does not “crowd out” turfgrasses, but once it is established, grass plants will not spread into mossy areas.
In order to obtain effective control of moss consider the reasons why it began to grow in the lawn. Attempts to eradicate moss are rarely effective unless there is actively-growing turf to take its place.
Moss in lawns is usually the result of conditions that are not beneficial to good growth of turf. Moss is most commonly associated with shallow soils; poor soil fertility; low soil pH (acid soils); heavy shade; and excessive moisture. If any of these factors are limiting turf growth, moss can invade the lawn and establish itself.
For effective moss control start by modifying the site conditions to favor lawn grasses. Too much shade for acceptable grass growth is a common underlying cause for moss invasion. Pruning trees and shrubs to improve air circulation and light penetration is a good starting point. Make sure the proper shade tolerant grass is being used.
Look at the soil conditions. A soil test can be helpful to determine if the soil pH is too high or too low. Reduce soil compaction by core aerifying.
Evaluate lawn care procedures, especially fertilizing. Lawns need adequate fertilization, in particular nitrogen. Established lawns in shady areas need about 2 to 4 pounds of actual nitrogen per 1,000 square feet per season.
Also be sure lawn care practices are sound. Short mowing may be a source of the moss problem; a cutting height range of 2 1/2 to 3 1/2 inches is ideal for most lawn grasses. Mow on a regular basis based on the rate of lawn growth to avoid removing more than one-third of the leaf blade at each mowing. Avoid excessive watering. Water based on lawn needs.
Materials such as copper sulfate sprayed over the moss do eliminate it from the lawn. However, copper sulfate only cures the symptom, the moss. They do not change the conditions responsible for its presence.
University of Nebraska-Lincoln Extension in Lancaster County is your on-line yard and garden educational resource. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office