Plan the perfect garden with our interactive tool →

Will Laundry Detergent Kill Grass?

...
Jupiterimages/Creatas/Getty Images

Grass thrives under particular conditions, and seemingly harmless conditions can kill it. A substance such as laundry detergent, while safe for your clothes, can mean the end of your well-kept lawn. Whether you spill detergent accidentally or use it as an insecticide, use caution to prevent it from killing your grass.

Safety for Grass

Though soaps are not inherently harmful to grass, laundry detergent specifically contains ingredients that damage grass, though not necessarily kill it. When using laundry detergent as part of an insecticidal spray, dilute it heavily with water. The University of Rhode Island recommends a dilution of no more than 3 percent laundry detergent, or slightly less than 2 tbsp. of detergent for every quart of water.

Water

According to the American Rhododendron Society, water is an effective insecticide without the damaging effects of laundry detergent. Water-stressed plants are often more susceptible to insect pests, and spider mites and aphids can be kept in check with regular watering. Water your lawn before trying other methods.

Preventing Damage

Water can also stop the damaging effects of laundry detergent. Just as soaking grass with water dissolves harmful salts, it also dilutes laundry detergent and disperses it in the area. Soak the grass with 1 gallon of water for every 1/2 cup of detergent you estimate you spilled. This produces a 3-percent dilution of detergent, which is safe for grass.

Killing Grass Naturally

If you want to kill grass, use salt instead of laundry detergent. Unlike laundry detergent, salt is sure to kill grass rather than damage it. Cover the unwanted grass with salt to dry it out and deprive it of nutrients. Whiteness in the soil is a sign the salt is working.

Related Articles

The Effects of Antifreeze on Grass
The Effects of Antifreeze on Grass
How to Use Salt to Kill Grass
How to Use Salt to Kill Grass
Will Borax Kill Grass?
Will Borax Kill Grass?
How to Kill Grass With Salt
How to Kill Grass With Salt
How to Kill Garden Bermuda Grass Without Chemicals
How to Kill Garden Bermuda Grass Without Chemicals
How to Rid Grass From Growing in Gravel
How to Rid Grass From Growing in Gravel
After Fertilizing Your Lawn, When Is it Safe to Let Your Pets on the Lawn
After Fertilizing Your Lawn, When Is it Safe to Let...
How to Mix Groundwork Weed Killer
How to Mix Groundwork Weed Killer
Will Household Bleach Kill Grass?
Will Household Bleach Kill Grass?
How to Kill Water Grass
How to Kill Water Grass
How to Use Saltwater to Kill Weeds in St. Augustine Grass
How to Use Saltwater to Kill Weeds in St. Augustine...
How to Get Rid of Water Grass
How to Get Rid of Water Grass
How to Use a Tarp to Kill Grass
How to Use a Tarp to Kill Grass
Garden Guides
×