PPDL Picture of the Week

April, 30, 2018

Moss Control in Home Lawns

John Orick , Purdue Master Gardener State Coordinator Department of Horticulture and Landscape Architecture

Mosses are small plants that look like a mass of fine stems that grow in a variety of conditions ranging from very wet to dry soils. They vary in size and are without a root system, but grow root-like filaments which attach to the soil or other substratum. Mosses can invade lawns with low fertility, poor drainage, heavy shade, soil compaction, poor air circulation, or a combination of these factors. Moss infestations in lawns are not caused by low soil pH. Under poor growing conditions as previously described, moss plants are able to out compete turfgrass and infest lawns thinned due to these poor growing conditions. Mosses are not harmful but many homeowners desire a thicker stand of turf vs. moss in their lawns.


The only permanent way to control moss in turf areas is to correct poor growing conditions causing the moss to out compete turfgrasses. The following lawn maintenance practices will help control moss infestations:


·       Fertilize lawns at least once per year. Late- August through November is the prime time to fertilize turf for recovery from summer stress and to maintain a dense, green, deeply rooted turf with optimum energy reserves for future growth.


·       Improve drainage. Some moss species thrive in wet conditions. Poor drainage can be sometimes be corrected by improving the surface grade of the soil but other drainage issues will require the installation of a tile drain.


·       Increase air circulation. Areas surrounded by trees may block air circulation over the turf. Pruning tree limbs or removing plants when feasible, may help increase air movement over turf plants and help dry the soil surface.


·       Provide more light. Growing turf in dense shade can be very challenging and this situation often forces the homeowner to choose between growing turf or trees. When practical, remove trees or prune tree limbs to provide more light to turf. In many cases and when soil drainage is adequate, homeowners may choose to grow an alternative ornamental plant like a shade-loving groundcover, perennial or annual flowers suitable for dense shade.


·       Aerify or cultivate compacted soil. Many moss species are adapted to compacted soil conditions but turfgrass plants are not. Therefore, cultivating the soil through use of a hollow-tine core aerifier or a power rake can help loosen the soil and relieve compaction.


·       Seed areas to reestablish turf. Seed shade-adapted species under shade trees in thinned lawns. Use fine fescue species such as creeping red fescue, Chewings fescue, and hard fescue under shade trees in lawns in the northern 2/3 of Indiana. Use tall fescue in the southern 1/3 of Indiana. Late summer and early fall seeding dates have the best chance of establishing because it will provide the longest exposure to direct light during the fall before the tree’s deciduous foliage returns the next spring.




Publications and Related Websites:


Fertilizing Established Lawns (AY-22-W) https://www.extension.purdue.edu/extmedia/AY/AY-22-W.pdf


Establishing Turfgrass Areas From Seed (AY-3-W) https://www.extension.purdue.edu/extmedia/AY/AY-3-W.pdf

Improving Lawns in the Shade (AY-14) https://www.extension.purdue.edu/extmedia/AY/AY-14-W.pdf


Mowing, Dethatching, Aerifying, and Rolling Turf (AY-8-W) https://www.extension.purdue.edu/extmedia/AY/AY-8-W.pdf


Controlling Moss and Algae in Lawns, Turf Tip, 4/4/03 by Zac Reicher. https://turf.purdue.edu/tips/2003/moss44.htm

​Click image to enlarge

Photo 1: Moss in a home lawn (Photo by John Orick)

Photo 2: Close up of moss in a home lawn (Photo by John Orick)

Photo 3: Close up of moss plants (Photo by Aaron Patton)