How to Kill Unwanted Moss with Dish Soap

Moss can be a decorative ground cover when it grows where it's wanted, or it can be considered a nuisance weed when its thick mat of tiny green leaves and threadlike stems are unwanted. Though moss won't kill your grass, it can leave your lawn splotchy and uneven. Luckily, there are a few solutions to manage moss.

Ways to Kill Moss on Your Lawn

Traditional ways of eliminating moss include spreading iron sulfate moss killer. You can also get rid of moss in your lawn by making it less acidic by adding lime to the soil. Or, you can use good old sweat equity and rake out the living moss from your lawn. But the simplest, safest method is to use dish soap. Read on to learn what kills moss permanently in four steps using this recipe that costs pennies.

1. Mix Soap and Water

   Mix a small batch to kill a small patch of moss by combining 2 ounces of dish soap and 1 gallon of water in a garden hand sprayer bottle. Use gentle liquid dish soap, such as the original Dawn, which you'll find in most grocery stores.

   Use 4 ounces of dish soap in 2 gallons of water for larger areas and every 1,000 square feet of lawn.

2. Spray the Mixture on Moss

   Spray the mixture on the patches of moss. Holding the spray nozzle a couple of inches from the target area, drench the moss with the solution. Do not spray the grass, as the solution can also kill healthy grass.

3. Dig up Dead Moss and Roots

   Dig up the dead moss after 24 hours. It should have turned orange or brown and dried up. The dish detergent does not necessarily kill moss at the roots, so remove as much of the moss as possible. The surrounding grass will begin to grow over the patches.

4. Discard the Dead Moss and Reseed

   Take the dead moss to an isolated area to discard. Don't compost it or the moss spores could spread back into your lawn.

   Re-seed bare areas left by the dead moss in a few weeks, as the liquid soap can impede germination. Top the new grass seed with new, loose soil free of moss spores.

When to Apply the Moss Killer Solution

Late spring or early fall are the best times to kill lawn moss. Killing moss should always be done before seeding your lawn, which is best done in the early fall.

Always apply the dish detergent and water mixture when the grass is moist. also, check the weather to make sure there's no call for rain in the forecast within 24 hours of application.

Avoid using the dish liquid and water method for moss that appears on your roof. Moss on your roof should be quickly but gently removed with commercial preparations so your roof tiles remain undamaged.

Discouraging Lawn Moss Growth

If more moss appears on your lawn, it's safe to repeat the dish detergent treatment. Treatments like this are temporary, however. Address the underlying cause of moss growth to control its growth. That usually means testing the pH level of your soil. Moss likes acidic soil, so increase your soil's pH by adding lime, also called dolomitic lime. Lime makes your soil less acidic by adding more alkaline.

Though lawn lime adds nutrients to existing grass to encourage its growth, it won't directly kill moss. Lime can be added to your lawn between fall and early spring. Or, lime your yard before fall's first frost to give your soil all winter to absorb the lime.

Adding lime doesn't guarantee you'll never see another patch of moss. If the moss seems impossible to eradicate, especially if it's growing in a perpetually shady area, let it flourish and consider embracing the world of moss gardening.