How to Use Roundup to Kill Grass


Glyphosate herbicides such as Roundup are broad spectrum, meaning they'll kill all vegetation on which they're sprayed. Using Roundup on your lawn is one of the fastest ways to kill the grass, whether you want to kill your grass to make room for new shrubs, a new variety of grass or a walkway or garden structure. Avoid more labor-intensive methods like sod cutting and spray your yard with Roundup to start seeing results within a week.

Step 1

Avoid watering the grass for 24 hours before applying the Roundup to ensure a dry environment that will allow the Roundup to penetrate the grass at full strength. Wait for a dry day when there's little to no chance of rain.

Step 2

Pour the Roundup Ready-to-Use product into a garden sprayer, if needed; some bottles of Roundup include a built-in spray applicator.

Step 3

Mist the Roundup product onto the grass, applying an even mist onto all exposed grass surfaces. Start at one end of the lawn and walk away from the direction of the spray to ensure that you don't walk on the freshly sprayed herbicide.

Step 4

Wait for the Roundup to kill the grass. Brown and wilting grass will begin appear within six hours of applying the Roundup Ready-to-Use product, according to Monsanto, manufacturer of Roundup.

Tips and Warnings

  • Wear protective gloves and safety goggles when handling any herbicide product. All glyphosate-based herbicides such as Roundup will kill grass. Common alternatives--including 2,4-Dichlorophenoxyacetic acid, also known as 2,4-D--may not be effective against many grass species.

Things You'll Need

  • Roundup Ready-to-Use
  • Garden sprayer (optional)
  • Protective gloves and safety goggles


  • "The Lawn Bible: How to Keep It Green, Groomed and Growing Every Season of the Year"; David Mellor; 2003
  • "Lawns: Your Guide to a Beautiful Yard"; Nick Christians, et al.; 2007
  • Monsanto: Roundup Chart
Keywords: kill grass, Roundup on grass, remove grass

About this Author

Josh Duvauchelle is an editor and journalist with more than 10 years' experience. His work has appeared in various magazines, including "Honolulu Magazine," which has more paid subscribers than any other magazine in Hawaii. He graduated with honors from Trinity Western University, holding a Bachelor of Arts in professional communications, and earned a certificate in applied leadership and public affairs from the Laurentian Leadership Centre.