Is Ammonia Used for Grass & Weed Killer?

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Ammonia is a common ingredient in grass and weed killer.

Ammonia is a common ingredient in many commercial and homemade grass and weed killing solutions. While ammonia is a natural substance, it is toxic to humans and animals and can also harm your soil. Despite its effectiveness in removing weeds and grass, always consider its harmful effects before deciding to use it in your yard.

Ammonia as a Weed & Grass Killer

Ammonia is a common ingredient in many weed and plant killers. Unlike many weed killers, however, ammonia is not selective and will kill any plant it comes into contact with. Thus, if you spray it on weeds in your lawn, it will not only kill the weeds but the grass that grows around it. Ammonia kills the plant by attacking its roots as well as its top growth. This method may take longer to see results, but it is effective it killing grass and weeds.

Effects to the Plants

Ammonia works to kill plants by attaching to the plant's cell wall and slowly eating it away. This causes rapid dehydration, which will kill all of the top growth. If you don't spray the entire surface of the plant, part of it will survive and it could regrow.

Positive Effects of Ammonia

When applied in very small and diluted doses, ammonia will actually nourishes the weeds and grass on your lawn. This is because ammonia is a common and cheap source of nitrogen, which is a necessary mineral for plant growth. Most solutions include ammonia, a carbonated beverage, dish soap and beer. Apply the solution to the plant every three weeks.

Environmental Issues

Not all types of ammonia-based weed killers break down into nitrogen when they sit in the soil, which causes some concerns. If it does not break down, an excess amount of ammonia will leech into the soil and could render it infertile over a period of time. For this reason, some European countries, such as the United Kingdom, prohibit the use of certain types of ammonia-based weed and grass killers.


Kaye Wagner

Kaye Wagner has been working in the fields of journalism and public relations since 2006 and is a recipient of a National Hearst Award. She is particularly interested in home-and-garden projects, as well as beauty and fashion writing. An avid traveler, she also writes travel reviews and guides. Wagner earned a Bachelor of Arts in journalism from Brigham Young University.