People frequently ask how to get rid of moss in their lawns, particularly in the spring. Although there are some chemicals that may give a “quick fix,” moss will return unless environmental modifications are made. Though typically thought of as a shade problem, moss may appear for a number of reasons. Moss doesn’t invade a healthy lawn. In addition to shade, low fertility, poor soil drainage, compacted soils, poor air circulation and high humidity may encourage moss invasion of the lawn. Acid soil may contribute to the growth of moss, but lime should not be applied to Minnesota’s soils without a soil test because many areas of the state have sufficient lime for most plants. Poor lawn care practices may also contribute to moss problems. General neglect, irregular mowing, lack of fertilizer and overwatering commonly lead to moss problems. The best way to discourage moss is to grow better turf. Because too much shade is often an underlying cause for moss invasion, a good place to start is by pruning trees and shrubs. Areas of low fertility can be fertilized to encourage grass growth to crowd out moss. Yearly power raking and core aerification improve drainage and lessen compaction for better root development and more vigorous grass growth. After correcting the factors that cause moss problems, bare spots should be raked out by hand, or cultivated and reseeded with a mixture suitable for light conditions. For shady spots, use 60 percent creeping red fescue and 40 percent Nugget or other common Kentucky bluegrass. Moss can also be killed by using five ounces of copper sulfate in four gallons of water per 1,000 square feet. Dead moss can be raked out and thin spots reseeded. If grass doesn’t grow well after several years of effort, and moss persists in shady areas, you may have to choose another alternative. There are some shade tolerant groundcovers that work well, and if all else fails, you can use decorative mulch under the trees.
