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How to Mix Weed Killer

By Damon Hildebrand ; Updated September 21, 2017
Weed killer must be mixed properly.
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Effective weed control for young gardens and spring lawns requires constant vigilance. When non-fatal weapons in the gardener’s arsenal of tricks aren’t enough to combat the problem, more serious reinforcements may be called in. Glyphosate is more than likely the weed killer of choice. As the primary ingredient in leading weed-killing products, it is the most-used herbicide to eradicate weeds and unwanted grass. Often purchased as a concentrate so as to provide maximum coverage, it must be mixed with water to the ratio provided on the label.

Use an appropriately sized container for mixing the water and glyphosate concentrated weed killer. A quantity of one gallon is the standard volume used to calculate the ratio of concentrated weed killer to be mixed. If container is one-half gallon, divide the recommended amount of weed killer to be mixed by half. If container to be used holds two gallons, double the amount of week killer to be mixed.

Measure out the appropriate amount of glyphosate for mixing with one gallon of clean water. For newly sprouted weeds, the ratio is 3 fluid oz. of weed killer to 1 gallon of water. For larger weeds, mix 6 fluid oz. per gallon of water.

Fill the container halfway to the desired level. Pour the measured weed killer into the water, and finish filling container with water. Avoid spraying the water into the container using a garden hose nozzle; weed killer will foam excessively and could splash out. Instead, use a slow stream directly from the garden hose or watering can to fill the container.

Use an old handle or dowel--something that is straight--to stir the mixture completely in the container until it is well-mixed.


Things You Will Need

  • Mixing container
  • Mixing paddler or tool handle
  • Graduated measuring cup
  • Water


  • Agitating the water and weed killer mixture will cause excessive foaming and will make proper mix ratio more difficult to obtain.


  • Using more weed killer than is recommended on the product label may damage or kill lawn or surrounding plants.
  • Do not allow children or pets to play or enter the treated area for 24 hours after treatment.

About the Author


Damon Hildebrand is a retired U.S. Navy veteran. He has more than 15 years within the oil and gas industry in both technical and managerial positions. Hildebrand has been a technical writer and communicator for the last four years. He is a certified specialists in lubrication and tribology, as well as a certified maintenance and reliability professional.