It’s rare for dish soap and grass to come into contact with one another. Chances are, if you’re on this page, you’re in one of two scenarios. In the first, you could have heard that dish soap is an effective herbicide. In the process of taking out those weeds, you may have spilled soapy water on your lawn. Or perhaps you were in the middle of a deep clean but some of the dish soap and water splashed on your lawn and now you’re asking, “Will dish soap kill grass?”
Will Dish Soap Kill Grass?
Yes, in concentrated form, dish soap will kill grass. Dish soap or dishwashing liquid contains chemicals that are meant to remove grease and food buildup from dishes. Most dish “soaps” are detergents or synthetic chemicals meant to break down fats and oils. Plants, including grass, are just as susceptible to dish soap alive as they are once they’ve been cooked.
The Effect of Dish Soap on Lawns
Getting dish soap directly on your lawn is a sure way to end up with dead, dried-up patches of grass, no matter the type. Concentrated dishwashing liquid breaks down the healthy, oil-based tissue in the plant. This leads to leaves that can no longer retain moisture. Combined with a little heat and sunlight, that means you could end up with patches of crispy, brown grass in as little as a single day.
Is Dish Soap an Effective Lawn Pesticide?
Many people that ask “Will dish soap kill grubs?” are met with a myth. Drowning any patch of your lawn with water, even clean water, will cause the grubs to come to the surface. Have you ever gone for a walk after it rains? There are worms all over the sidewalks. Same principle. Nothing likes to be drenched in water, even if it’s something that typically lives underground.
If you use a lawn-safe concentration of dish soap and water, the grubs will be unaffected and eventually bury themselves back into your lawn. You could always use this to force the grubs out for collection, but that gets old fast. There are better, water-smart solutions like milky spore or nematodes.
How to Clean Up Spilled Dish Soap on Your Lawn
The best way to clean up spilled dish soap is to dilute it and “wash” the soap off of your lawn. Once diluted and no longer in direct contact with the blades of grass, the soap should be unable to harm your lawn.
Even if you spill well-diluted soapy water, an extra rinse is never a bad idea. Many dishwashing liquids contain substances that, even though they appear to have washed away, are still stuck to the waxy coating on the outside of the grass. Disturbing this coating leaves your lawn susceptible to all sorts of pests and diseases.
Related Article: What Kills Grass? A Comprehensive Guide
Will Any Dish Soap Hurt Grass?
Soap, in general, doesn’t hurt grass all that much and can be a useful insecticide. The problem is that most “dish soap” isn’t soap at all but is a form of “detergent”. No matter if you’re asking, “Will Dawn Dish Soap Kill Grass?” or “Will Seventh Generation soap harm my lawn?” the answer would be the same. They will both break down the oils and waxes within each blade of grass and cause it to wither and die.
Does Dish Soap Kill Grass Permanently?
If enough soap is spread on each blade of grass, especially if that plant is a broadleaf variety, then that plant will likely die and not come back. However, established lawns are often more resilient than they are given credit for. If the soap is rinsed off within at least a few hours of application or a spill, the grass should come back after a few days or weeks.
Will Dish Soap Kill Grass Seeds?
Dish soap may or may not kill your grass seeds, depending on the type of dish soap you’re using. If you got antibacterial or antimicrobial dish soap or detergent on your seeds, those seeds will no longer sprout. If spilled on the ground, these types of dish soap can disrupt the microbial balance of your soil and roll out the welcome mat for dozens of pests and diseases.
Is Dish Soap A Good Way to Prevent Grass From Spreading?
If you want to clean up the grass working its way into the cracks of your sidewalk or around your hedges and flowerbeds, coating the grass lightly with dish soap from the bottle will likely do the trick. If you do plan to go this route, make sure to apply the soap in the middle of the day while the sun is out and never use antibacterial soap or detergent.
Detergents Will Harm Any Plant They Touch
Dish soap is an ambiguous term for many detergent-based products. They can easily break down the protective coating on the outside of blades of grass or the leaves and stems of plants, leaving them vulnerable. This could help if you need to spot-treat an unruly patch of grass but it could also lead to dead patches if you accidentally spill detergent directly on your lawn. However, with quick action and plenty of water, it’s easy to save your lawn from a dish detergent spill.
Thanks for the info. I’m trying to clean the mold off my concrete patio and usually use a diluted bleach solution, but now am afraid that will kill my plants. Is there anything I can use with a high pressure hose to clean that?
Hi Frank,
Whenever I wash my patio or driveway, I use a diluted bleach solution in a handheld sprayer. A small, inexpensive pump spray allows you to target the area using a lot less bleach. If you let the bleach soak for 5 or so minutes and then hit it with your pressure washer, you should be ok. Once I have finished, I make sure to give the surrounding area a good soak with my garden hose to wash any bleach away. The local pressure washer guys where I live say that they use a 4:1 (water: bleach) mix without any issues with surrounding plants and vegetation.
I’ve been using this method for a long time, and I’ve never had any issues. Just don’t forget to soak the surrounding area once you have finished.
Thanks for the question.
Tom.