What Chemicals Will Kill Moss?

Potassium salt from fatty acids is known to kill different types of moss, according to Garden Guides. Zinc is another moss killer, and it comes in different forms such as zinc-copper sulfate and zinc chloride. One particular zinc-based solution is zinc chloride at a 13 percent concentrate in powder form. Gardening Know How adds that ferrous sulfate and ferrous ammonium sulfate are chemicals normally used in moss sprays.

SF Gate notes that killing moss on a lawn requires 3 tablespoons of baking soda and a quart of warm water. This is a type of solution that works best during sunny days, and complete saturation of the chemical on moss is necessary, leaving it on for 20 minutes and applying more bleach as necessary. For moss found on walkways, mixing equal amounts of chlorine bleach and water is another effective solution. The moss should be scraped off before applying the solution, and the chemical should sit on the area anywhere from 15 to 20 minutes.

Killing moss on a roof also requires removing it first before applying 4 scoops of oxygen bleach and 4 gallons of warm water. This solution should be poured over where the moss settled, and left for at least 20 minutes. Bradly Lewis Home Maintenance mentions laundry detergent as another way of killing moss on roofs, but there is a chance of granule loss and damage to the structure, if it is not washed away after application.