While raking off leaves from your lawn this fall perhaps you have noticed an area or two has more moss than grass. There are a variety of reasons why moss occurs in lawns.

One key point involving moss issues in lawns is the fact moss does not invade vigorous turf. Instead, it develops as turfgrasses thin out, but growing conditions are favorable for moss. Shade locations typically see the most moss as lawn grasses, even shade tolerant species, do not thrive in shade, but moss does.

Several soil factors also help allow moss to become the prevalent plant, regardless of shade level. Poor drainage, compaction, low fertility, and unfavorable soil pH all can be unwelcome news for grasses, yet mosses tolerate them much better. Once again, grasses thin and mosses or unwanted plants such as ground ivy (which is an entire column topic by itself) take over.

Keeping these factors in mind, the first step in dealing with unwanted moss in your yard is to determine all site conditions that favor moss over grass and make modifications. Assuming shade is a factor, some selective tree pruning before next season may allow more light to reach the soil. Increasing air circulation over dense shade areas can also be helpful. Mow shade lawns about 3 inches high. Reseed next spring with a quality shade lawn mix containing fine fescues, which include creeping red, chewings, and hard fescues.

Core aerating may help solve soil surface drainage and compaction issues. Time may be running out for this fall but consider this practice in 2025. The best core aerators pull up cores and drop them on the soil surface. This will also help if thatch is an issue in your lawn.

Soil test results will reveal the soil pH, which can be corrected if found to be too alkaline (add sulfur) or acidic (add limestone). Do not assume moss is always growing on acidic soil; use a soil test to confirm that is the case. Routine limestone applications are not suggested without determining if an acidic soil is present.

Make sure your lawn is fertilized properly. Less fertilizer is suggested for grasses in shade lawns. Compared to those in full sun, shade lawns need lower nutrient amounts, especially nitrogen.

Another consideration in dealing with thinning lawns full of moss or weeds is to consider replacing grass with shade tolerant ground covers or other alternative shade plants. Research all the possibilities this off-season and be ready with a plan next spring.