Last Updated on March 29, 2021

What Does Bleach Do To Grass?

Most households own a bottle or two of bleach. Bleach comes in handy for cleaning and laundry.

But, what about your yard? Will bleach damage your lawn? Can it be used to control weeds or kill unwanted grass?

Or, maybe you’ve accidentally spilled bleach on your lawn. Will it recover? Will you need to plant new grass?

What is Bleach?

Chlorine Bleach

According to the Clorox website, the active ingredient in chlorine bleach is sodium hypochlorite. Most household bleach products contain 5-6% sodium hypochlorite.

This ingredient is derived from salt. Once the sodium hypochlorite breaks down, 95% of the product returns to its original state as oxidized salt and water.

Chlorine bleach is most commonly used for cleaning, disinfecting, and laundry. It may also be used as a pesticide. If you buy a bottle labeled ‘bleach’ from the store, it is most likely chlorine bleach.

Oxygenated Bleach

Oxygenated bleach, or oxi bleach, or also known as non-chlorine bleach, usually contains hydrogen peroxide and sodium. Sometimes, it will also contain washing soda. It is less caustic than bleach and safe to use on all laundry.

It may not be as tough on stains, but it will be gentler on skin and laundry. Oxygen bleach is usually clearly labeled as “oxygen bleach” to not be confused with chlorine bleach.

Will Grass Grow Back After Bleach Has Been Spilled On It?

Chlorine bleach will permanently kill grass and other plants. Bleach breaks down into salt. Salt in your soil will destroy all the beneficial microbes that usually live there. The grass will be robbed of nutrients and will starve.

Wait until the area has recovered before attempting to plant new grass. This will depend on the amount of bleach spilled and the pH of your yard. It could recover after a few rainfalls, or it could take as long as a year.

Test the soil pH to determine if the ground is ready for new grass. The pH of the soil should be between 5 and 7. Try to reseed or lay new sod in the area. If the soil is recovered, then the new grass should grow.

Does Bleach Kill Weeds Permanently?

Undiluted bleach will kill weeds! Simply spray or pour cups of bleach onto weeds growing through sidewalk cracks, and they will die. As bleach may damage grass, soil, and other plants and flowers, apply it carefully!

After one to two days, the weeds are dead, and you can pull them out. If you are careful to remove the root, the weed should not grow back.

How Long Does it Take For Bleach to Kill Grass?

It takes three to four days after grass has been exposed to grass before the grass dies. The grass will starve to death because the bleach depletes the soil of nutrients.

What Does Bleach Do to Soil?

Bleach is made from salt. The salt will damage plants and soil by killing all the microbes that help keep the soil healthy. Chlorine bleach has a pH of 11, and soil usually has a pH level between 5 and 7. The bleach will raise the ground’s pH, which then blocks the soil’s naturally occurring nutrients.

A high concentration of bleach applied to soil could alter the soil’s pH for an entire planting season! If you have bleach on your soil, test the pH before planting again.

Final Thoughts

Pouring or spraying bleach in your yard is generally not a good idea. The bleach may kill your weeds, but it could also alter the soil, and kill any grass or plants in the area.

Only use diluted bleach to kill grass or weeds if you don’t have any plans to plant anything else in the area. For example, weeds or grass growing out of cracks in a patio may be killed by bleach without damage to nearby plants or grass. Otherwise, look for other methods of weed control.


Author: Matt Hagens

Matt Hagens

Hi, I’m Matt the owner of Obsessed Lawn. I love to be outside working on my lawn, planning my next project. I created this website to help people like you find the best products for yard care and great advice. Learn more about me and find me on Facebook.