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Roundup Weed Killer Instructions

Roundup herbicide is glyphosate and is manufactured by The Scotts Company. Roundup is a broad spectrum herbicide that is non-selective. Almost any plant it contacts will die. Different types of Roundup are available for different needs. Besides the all-purpose Roundup Concentrate, you will find Roundup Poison Ivy Plus Tough Brush Killer, Roundup Extended Control Weed and Grass Killer and other concentrations for various purposes. Follow the exact label directions for the product you choose.

Fill your sprayer with the exact volume of water indicated on the mixing chart on the label. To use the regular Roundup Concentrate, mix 3 ounces of Roundup with 1 gallon of water. If you have a standard liquid measuring cup, 3 ounces is 3/8 of a cup. The measuring cup you use with Roundup should be labeled and stored with garden supplies to be used only with Roundup.

At the 3 ounce per 1 gallon rate, 1 quart of Roundup will make 10 gallons of spray.

Cap the sprayer. Swirl the sprayer slowly to stir the liquid, then pump to pressurize the sprayer.

Spray the solution directly on the plants you want to eradicate. Spray the leaves until they are completely wet. If some Roundup inadvertently lands on a plant you want to keep, rinse it off immediately with clean water. Roundup dries on the plants in 30 minutes and it is rainproof at that time.

Apply Roundup anytime weeds are growing. A warm, sunny day is best, when the weather is dry. The air temperature should be above 60 degrees F. Avoid spraying on breezy days.

Clean the sprayer. Unused Roundup that is already diluted will remain potent for six months in storage. Undiluted Roundup in the original bottle will remain potent for eight years.

Look for results within 24 hours. Leaves should be yellowing by that time. Complete kill may take up to two weeks. Roundup kills the entire weed, from the leaves to the root.


It is impossible to completely clean all traces of Roundup or any other chemical from a sprayer. Label the sprayer you use with Roundup and use it only for Roundup. Quarantine the measuring cup so it will never be used for food.

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