Q. Some areas of my lawn are covered with moss. What can I do about it?
There are a number of reasons for moss to invade a lawn. These may be summarized as follows:
1. The area is too shady. Lack of sunlight is the most common cause in most home gardens. This could be because the lawn area is in the shade of trees, hedges or buildings. Shade trees may be thinned to provide more light under their canopy. It may be possible to lower the height of hedges but this may not be desirable. Obviously, it is more difficult to deal with buildings!
2. The location is too wet or waterlogged. It may be possible to correct this problem by improving the drainage. If you are using a sprinkler system check that it is set to provide the minimum of necessary water. Waterlogged areas may need a subsoil drainage system.
3. The pH of the soil is too low (i.e. conditions are too acidic). A pH of 6 – 7 is ideal for lawns. Test the pH of the soil in the affected area and if it 4 or 5 then add lime to raise the pH to an optimum level.
4. The area is compacted. Grass roots need good a good supply of oxygen and this is not available in compacted areas. The problem can be solved by aerating the lawn, with a fork, if it is a small area, or with a commercial plug or spike aerator for larger areas.
5. Poor fertility. Grass needs fertile soil in order to grow well. Weak or thin turf will provide an opportunity for mosses and other weeds to overgrow it. Have your soil tested for its levels of major nutrients (your local Cooperative Extension Service can do this for a small fee). Then correct the problem with a suitable fertilizer.
Moss can also be controlled by chemical treatments but this is not completely successful if the underlying problem in not solved. Treatment with iron sulfate or ferrous ammonium sulfate (1 pound per 1000 sq. ft.) is recommended. Water well after applying the chemicals and then rake away the dead moss after it has turned black. Reseed the area with a shade tolerant grass seed mixture.
Another way of thinking about this problem is to follow the old adage –“If life gives you a lemon, make lemonade”. Here is a link to an article on moss gardening. http://www.bbg.org/gardening/article/the_simple_art_of_moss_gardening
Courtesy of the NYBG Plant Information Service