How to deal with Moss In The Lawn

Moss is a common problem in shade filled lawns, and if your yard has this problem then the question you need to ask isn't so much "How do I get rid of it," but "Why is it here in the first place?"

Moss is one of the dinosaurs of the horticultural world. It's a plant that has been around since the first plants came into being, and as a result it's needs are very basic. Moss isn't really as much a problem plant as it is an indicator of what is really going on at the soil line in your yard and garden. Moss will appear if your soil is compacted, features a low ph, a lack of direct sunlight, and a lack of organic material. It thrives in rocky spots, moist and poorly drained spots, and impenetreble, hard-pan, construction-grade soil.

One of the first things you need to do when you have a Moss problem is to really examine the location it's living in and see if the soil you currently have is capable of supporting another type of plant. Are your issues simply poor soil and drainage? Do you have a shady lot? And lastly, are your plans for your yard the antithesis of what is naturally sustainable? Do yourself a favor and tackle those questions in order.

Mosses, like most lawn weeds, primarily take advantage of bare areas but do not kill out existing grass as some people believe. Bare areas in lawn can be result from several causes. Unsuitable grass varieties, poor drainage, drought, soil compaction, excessive shade, thatch accumulation, poor fertility, highly acidic soil diseases, improper mowing and other cultural practices are common reasons for turf failure leading to moss or other weed problems. Improving these factors to encourage thick, healthy grass is the key to long term prevention.

Moss can be killed with products, ferrous ammonium sulfate, including Moss-Out, Moss-Kil, Rid-Moss, and a variety of Lawn Fertilizers with Moss Control; or moss & algae killing soaps such as Safer's. Personally I have never had much luck any of these. I prefer to purchase a small bag of Ironite and sprinkle it on the moss with a parmesan cheese shaker None of these materials pose serious threats to the environment; in fact iron and sulfur are essential nutrients for grasses and tend to improve their color. Although these products will kill existing moss, unless the underlying conditions are changed, moss or other weeds are likely to reappear.

Poorly adapted varieties of grass may fail due to cool temperatures, inadequate drainage, or prevalent diseases. Poor drainage and soil compaction can cause roots to suffocate or be subject to disease. Thatch and soil compaction can impede water movement to grass roots, leading to drought stress.

Raising the soil pH with agricultural or dolomitic lime can improve availability of nutrients and supply calcium and thus helping the turf grow better, but will not kill moss directly. The following steps will generally control existing moss and discourage it in the future:

1. Use a Ironite to kill existing moss in late winter or early spring.
   
2. Put Garden Lime down at a heavy rate to condition soil and reduce acid.
   
3. Dethatch or rake out dead moss, or skip step (1) and dethatch or rake with more vigor.
   
4. Overseed bare areas with a mixture turftype ryegrasses or ryegrass/fescue blend.
   
5. Topdress seeds with about l/4 inch of loose weed-free soil, potting mix, or peat moss.
   
6. Keep moist until seedlings are established.
   
7. Maintain the lawn according to recommendations in the reducing-lawn-maintenance.html