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How much Tenacity per gallon of water?

Tenacity is a selective pre-emergent and post-emergent herbicide. It contains a formulation that can control or kill weeds on lawns and turfgrass.

Its active ingredient is Mesotrione 40%, which provides year-long control of more than 40 invasive plants, including chickweed and crabgrass.

But Tenacity only becomes effective depending on how you mix the herbicide.

So, how much Tenacity do you mix with a gallon of water?

The amount of Tenacity to use will depend on the area you want to treat. Furthermore, it will depend on whether you want to use the herbicide for pre- or post-emergent treatment.

The recommended mix per gallon is one teaspoon. But since the amount of Tenacity will depend on the grass, most grasses can die if you apply eight ounces of Tenacity per acre. Therefore, the best mixture would be adding five ounces of Tenacity per 30 gallons of water per acre.

However, if your area has perennial ryegrass and fine fescue, consider increasing the amount. That is because the grasses are sensitive to Tenacity.

Furthermore, if you have St Augustine Grass, note that it can only handle four ounces of Tenacity per 30 gallons of water per acre.

Tenacity Herbicide


How much Tenacity do I need for a 2-gallon sprayer?

If you have a 2-gallon sprayer, mix two tablespoons of Tenacity with two gallons of water.

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However, you should also consider other factors, such as the type of grass on your lawn.

How much is Tenacity and surfactant per gallon?

If you have one gallon of water, the mixing ratios will change. In this case, you will have to add one and a half teaspoons of your preferred surfactant.

Therefore, your ratio will be one part of Tenacity herbicide with three parts of surfactant to treat growing weeds.

Alternatively, depending on the surfactant, you will have to add 1-2 teaspoons of the product per one gallon of water.

NOTE: Surfactant, also known as a surface-acting agent, reduces the surface tension of water in herbicide formulations.

Ideally, you only add Tenacity with water and apply it to the grass to kill it. However, the application will fall into the soil instantly.

But when you add a surfactant, it will target the weed instead of falling onto the soil.

How much Tenacity per gallon of water in 1000 sq.ft?

One teaspoon of Tenacity in one gallon of water is enough to treat an area of 1,000 square feet.

As explained above, you should also consider the type of grass on your lawn.

How does the Tenacity herbicide work?

Tenacity has an active ingredient called Mesotrione. When applied to a growing plant, the chemical inhibits the plant’s photosynthesis as it moves through its cell structure.

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The chemical prevents the plant from creating enough food needed for growth. Since the plant does not have enough food, it cannot grow or maintain its biomass.

In addition, when used for pre-emergent treatment, weeds absorb Tenacity as they emerge from the soil.

How do you apply Tenacity?

Applying Tenacity will depend on many factors. For example, the square footage of the area you want to treat will help you determine the amount of Tenacity you require.

Therefore, multiply the length and width of your lawn or garden to get the square footage.

The second step is determining the grass you want to kill in that area. Again, that is because the grass species will affect the application rate.

Tenacity herbicide

If you have a large area, the application rate should be between four and eight ounces of Tenacity per 30 gallons of water per acre.

But if you have a smaller space and want a spot treatment, use one teaspoon of the herbicide in one gallon of water to treat an area of 1,000 square feet.

Assuming you have an area of 2,000 square feet, mix two teaspoons of Tenacity with two gallons of water.

After doing your calculations and determining how much you require, proceed as follows:

  • Fill your sprayer halfway with water.
  • Add the amount of Tenacity you have determined to the water.
  • Shake the mixture.
  • Add the rest of the water to the sprayer and shake again.
  • Apply the solution to the unwanted plants.
  • Ensure you apply the chemical selectively to the weeds.
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When applying the chemical, it is best practice to use a fan-spray nozzle because it ensures even coverage.

Furthermore, it may be necessary to repeat the treatment after two or three weeks of application to improve post-emergent weed control.

Furthermore, consider adding a non-ionic surfactant to your mixture in a post-emergent application. The surfactant will increase the absorption, translocation, and sticking of Tenacity on the unwanted plants.

When is the best time to use Tenacity?

Tenacity is a post-emergent and pre-emergent herbicide. Therefore, for a post-emergent treatment, use the chemical when the plants are actively growing on your lawn.

But for a pre-emergent treatment, use the herbicide during fall and early spring.

How fast does Tenacity work?

When applied to young and actively growing plants, the plant absorbs the chemical as it translocates throughout its cell structure.

As a result, suppression of the plant occurs, thus disrupting photosynthesis. The entire process will eventually take two to three weeks for the plant to die.

What is the rainfast period for Tenacity?

Tenacity is rainfast within four hours.


Tenacity is an effective herbicide that you can use for the post-emergent and pre-emergent treatment of weeds on your lawn.

However, the chemical is only effective depending on how much you mix it with water. As a general rule, mix one teaspoon of Tenacity in one gallon of water.

The amount will be enough for spot treatment on 1,000 square feet. But for large spaces, use four to eight ounces of Tenacity per 30 gallons of water per acre.