Natural Moss-Killing Treatments

Lawns

• Unwanted moss on your lawns requires direct treatment of the moss itself, as well as soil improvement to make the area uninhabitable to future moss growth. Washington State University Extension recommends looking for organic moss killers that contain sulfur and iron, which not only kill moss, but encourage grass growth. Rake away dead moss before making improvements to your lawn. To make the area more grass-friendly and moss-hostile, raise the soil’s pH level with garden lime. Other natural anti-moss measures involve pruning trees to allow more sunlight, adding organic matter to the soil to improve its texture and drainage, and growing the grass variety best suited to your area. Check with your local extension service for recommended grass seed and soil amendments.

Trees

• In areas in which moss growth on trees is especially heavy, that extra weight may necessitate moss control, advises to Oregon State University Extension. Removing the moss in these cases helps reduce the chance of tree and limb damage, although these circumstances are rare. In some cases, homeowners simply dislike the look of excessive moss on woody shrubs and trees. Pruning branches or removing nearby trees to let in more sunlight helps control moss, as does physically tearing the moss from smaller trees and shrubs. For sturdier trees, consider using a power washer when the tree goes dormant in the winter, suggests OSU Extension.

Sidewalks and Patios

• Patios and paths often feature stones or bricks between which moss may flourish. Moss can even sometimes grow on these hard-scaping features. Use the sodium content of baking soda to create an earth-friendly and inexpensive death knell for moss. According to the Environmental Protection Agency, moss, weeds and other unwanted plants die when treated with baking soda. Sprinkle baking soda on moss growing between stones or cracks in sidewalks, paths and patios, as well as on any hard-scaping surfaces on which moss grows. Virginia Cooperative Extension additionally recommends mixing 1 ounce of lemon dish soap with 1 gallon water. Fill a spray bottle or backpack sprayer with some of this solution and apply it to mossy areas.

Roofs and Decking

• Moss on decks and other areas of foot traffic are problematic because they make the area slippery. Rooftop moss is considered unsightly by some homeowners, and carries the potential for shingle damage. Natural controls for roofs and decks are similar to those of other mossy areas; consider power washers and tree pruning. For areas that you can reach, sweeping or brushing away both moss and the shade-casting debris that allows moss to thrive may also solve the problem. Zinc strips nailed to roofs prevents moss from accumulating, especially around flashing for chimneys and skylights. Mineral-based powders and sprays for roofs and decking include potassium salts and formulas which use zinc or copper.