Wednesday, April 6, 2011
Moss is a common problem in many lawns across the country. Some people like the moss in their yard or garden because it is green, however, most of us want to get rid of it. Frequently our control of moss is futile if the conditions that favor moss are not understood. Moss produces spores. Spores travel through the air or on mowers transporting the spores from lawn to lawn. These spores are called protonemas, which produce buds that develop into moss. While most grasses are not growing in the winter, moss thrives and takes over lawn areas. In drier summer months, while grasses are actively growing, moss growth decreases. Moss cannot compete with vigorously growing turf.
Moss is caused by a number of conditions: insufficient sunlight due to shade, a low pH or acid soil, low soil fertility, heavy or compacted soil and soil that is too wet. I’ll bet you have seen one or more of these conditions in areas where moss is present.
Most of the time moss is growing because the conditions listed above do not favor the growing of turfgrass. The lack of sunlight in shaded areas is the main cause for grass to not flourish and moss to persist. As the tree canopy fills in during the spring season, less sunlight makes it through to the ground for the existing grass to perform photosynthesis. Over the grass growing months of March through November, this shaded condition only gets worse, not better. All grass seed needs some light to grow, even a few hours a day to thrive. In this case the only option is to thin out tree branches or perhaps remove some trees. Many of us do not like this option since we prefer to preserve the trees as well as avoid the expense of tree removal.
Low pH levels, or acid soil also promotes moss growth. Cool season turfgrasses thrive at a pH level between 6.0-6.7. Sometimes homeowners think that limestone applications will kill moss; it will not. If the other conditions listed above persist, moss can grow on limestone very nicely. Limestone applications like using Jonathan Green’s MAG-I-CAL, can be used to raise the soil pH or ‘sweeten’ the soil so turfgrasses thrive.
If you have low fertility levels in the soil this also is not conducive to growing grass. Open turf areas frequently are low on fertility levels. Proper fertilization with Jonathan Green lawn fertilizers will increase turf density, vigor and competitiveness. Traditionally shaded areas contain fescues, which do not require as much fertilizer as bluegrasses in the sunny areas. However, if you have not been on a regular feeding schedule of 2-4 applications of fertilizer per year, the moss may win the battle against your grass for that valuable growing space.
Compacted soil is another detriment in growing healthy grass. If the soil is compacted, oxygen, water and nutrients cannot get to the root systems of the grass to promote proper growth. Heavy soils are also associated with a high clay or silt content and may become waterlogged. Aerating these compacted areas mechanically along with an introduction of sand and/or some organic matter will help the grass grow and cause the moss to decline. Applications of gypsum after aeration will also help to improve the soil structure.
Grass does not grow well in excessively wet soils, however, the moss does. Wet soils are often associated with compacted or poorly drained soil situations. Also, too much irrigation can promote moss growth. Improve the soil drainage by incorporating soil additives or by using proper drain tubing to lower the water table and reduce moss growth.
How can we get rid of existing moss? Moss can be eradicated by mechanical means such as hard raking or scraping. You can also rent equipment to help in this backbreaking job if you are trying to fix a large area. There are also products available to help kill existing moss. These products include potassium salts of fatty acids; these are called Cryptocidal or ‘moss killing’ soaps. These products contain salts that will dehydrate or ‘burn’ the moss. These soaps act as contact killers and tend to bleach the moss to a whitish-yellow as it dies.
The other more common control is iron sulfate monohydrate. These iron-based products are available in both granular and liquid forms. For best results try Jonathan Green Lawn Moss Control. Do not apply these iron products to newly seeded areas until they have been mowed at least four times. Iron products can stain walkways and other areas, be careful when applying and blow off sidewalks after applications. These products will kill the moss usually within 7-10 days, turning the moss black. Do not apply Jonathan Green grass seed after the moss has died for 2-3 weeks. You may scrape the moss away; add Jonathan Green MAG-I-CAL limestone, some Jonathan Green Natural Beauty lawn fertilizer and some Jonathan Green Dense Shade mixture, which is a good shade tolerant grass seed or Jonathan Green Shady Nooks Mixture, which contains fescues, and/or rough bluegrass (poa trivialis), which can tolerant heavier shade conditions.
You can kill the moss, but if you do not correct the problems associated with moss growth you can bet that moss will reinvade your yard. If all else fails perhaps you will need to switch to a ground cover such as pachysandra, English ivy or myrtle. Don’t let moss be boss in your lawn! Happy spring!Back