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Learning the Basics

How Do Roundup® Weed & Grass Killer Products Work?

We reveal the technology behind our products’ weed-killing success.

Before you use a product around your landscape, it’s important to know how it works. That’s why we’re providing you with this handy info about the science behind many Roundup® Weed & Grass Killer products. Let’s get learning.

Illustration of a weed.

Right On Target

The main active ingredient in Roundup® Weed and Grass Killer products is glyphosate. It works by targeting an enzyme that is essential to plant growth.

Banish The Bad

After you apply Roundup® Weed & Grass Killer products to the leaves, glyphosate works its way through the plant, all the way down to the root. And just like that, R.I.P. weed.

Guard The Good

Word of warning — glyphosate doesn’t discriminate between unwanted weeds and wanted plants, so make sure that your Roundup® Weed & Grass Killer products don’t touch anything green that you want to keep.

To help you guard the good, we developed our unique Sure Shot® Wand for precision weed sharpshooting.

  • This handy wand gives a full two feet of reach for less bending over.

  • The battery-powered motor gives you a continuous spray without ever having to pump.

  • The clear dome shield allows you to apply Roundup® Ready-To-Use Weed & Grass Killer III point-blank. 
Rainproof clock illustration.

How long does it take?

After applying, people and pets can return to the treated area once it’s dry. Once the plant is dry, not even rain can stop Roundup® Weed & Grass Killer products from doing their job.

Most Roundup® Weed & Grass Killer products deliver visible results in a few hours, though some take a little bit longer. For Roundup® Max Control 365, it takes 12 hours to see visible results, but the trade-off is year-long hassle-free weed control.

To learn more about specific rainproof and visible results times for each product, check out the Product Usage Chart.

*Some Roundup® Weed & Grass Killer products contain additional active ingredients. See product labels for details.

Roundup lawn symbol.

Looking For Info On Killing Weeds In Your Lawn?

Roundup® For Lawns kills weeds, not lawns.

ROUNDUP® FOR LAWNS

Roundup® Weed & Grass Killer Concentrate Plus
Roundup® Weed & Grass Killer Concentrate Plus
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Jug of Roundup® Ready-To-Use Max Control 365 with Comfort Wand
Roundup® Ready-To-Use Max Control 365 with Comfort Wand
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Related Articles

Whether you are just starting out, maintaining or troubleshooting, you'll find advice and answers here for all your weed control needs.

Roundup® Weed & Grass Killer Products Control over 200 species of weeds.
Related Article
What Do Roundup® Weed & Grass Killer Products Control?

We know of over 200 types of weeds and grasses that our products can help you handle.

Learn More
A well-landscaped property with lots of garden beds, shrubs, and tress.
Related Article
Can I Treat Weeds With Roundup® Weed & Grass Killer Products When It's About to Rain?

Discover the answer right here.

Learn More
2021-04-19
2021-04-19
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The information on this site refers to Roundup® Weed & Grass Killer products and is for homeowner use. Always read and follow label directions.

*Consumer Guarantee: If for any reason you are not satisfied after using this product, simply send us original proof of purchase, and we will refund the purchase price.

Always read and follow label directions. Roundup, Roundup & design, FastAct, Roundup Extended Control and X design, Roundup® Precision Gel™, Pump 'N Go, Sure Shot and Draw the Line are trademarks of Monsanto Technology LLC. © 2021 Monsanto Company, worldwide rights reserved.