Although some people believe that moss growing on a lawn kills healthy grass, Washington State University Extension advises that it is, instead, an effect of turf failure. Bare patches in your lawn due to drought, too much shade, diseases and an array of other factors, provide ideal areas for moss to grow. To regain control of your lawn and successfully plant new grass, you must first rid the area of mossy patches. Bicarbonate of soda, also called baking soda, is a relatively safe herbicidal treatment that can help you kill moss in your yard.
Mix 354ml. bicarbonate of soda with 2 gallons of water in a garden sprayer.
Spray mossy areas thoroughly with the baking soda solution, preferably on a warm, sunny day.
Evaluate the mossy area in a few days, and if the moss is still alive, reapply baking soda and water to the area.
Moss will return if you do not remove the causative factors, like heavy shade and excessive moisture.