Tenacity herbicide: Mix Rate Calculator, Tips, Advice, and Your Complete Guide

Tenacity herbicide label
A new day brings a new herbicide, and today after reading this article you will know all about Tenacity herbicide.

Tenacity herbicide is made to change how you deal with pesky weeds and keep your garden, lawn, or farm looking great. It’s time to say goodbye to those annoying, stubborn weeds and welcome a fresh, healthy green space with Tenacity herbicide.

In this article, I’ll cover everything you need to know about Tenacity herbicide, from buying it to how, where, when, and how often to use it. You’ll learn important details like the kinds of weeds it kills, the active ingredient in Tenacity herbicide, and other options to consider.

I created a mix rate calculator for Tenacity herbicide to help you figure out how much water and herbicide you need. This calculator works with both acres and square feet and is very easy to use.

History of Tenacity herbicide

The American Cyanamid Company was the one that discovered one of the active ingredients used in the Tenacity herbicide in the 70s and developed it further.

In 2000, the Syngenta company decided to buy the rights to that specific compound from the American Cyanamid Company.

Syngenta developed and introduced Tenacity Herbicide in 2008. The Tenacity herbicide enjoyed tremendous success, becoming one of the most popular tools for controlling weeds.

What is tenacity herbicide?

Tenacity herbicide is a selective herbicide used for preemergence and postemergence control.

Tenacity herbicide can be applied on residential lawns, golf courses, athletic fields, parks, and other commercial properties like cemeteries, airports, or school grounds.

This selective herbicide can control a wide variety of weeds and is renowned for its ability to control weeds at the seedling stage effectively.

Tenacity herbicides can be found in both granular and liquid formulations.

The active ingredient in Tenacity herbicide

Tenacity herbicide has only one active ingredient called mesotrione.

Chemical structure of mesotrione - The active ingredient of Tenacity herbicide
Chemical structure of mesotrione – The active ingredient of Tenacity herbicide

Mesotrione is a selective herbicide part of the triketone chemical family. In 1977, the American Cyanamid Company discovered and developed mesotrione. This synthetic compound was introduced as a potential herbicide in 2000.

But how does this active ingredient work? This active ingredient in Tenacity herbicide inhibits photosynthesis in target weeds, leading to their death.

Tenacity herbicide contains 4 lbs. of active ingredient mesotrione per gallon.

How to use tenacity herbicide?

Tenacity herbicide is not complicated to use. However, everything depends on how you choose to use this selective herbicide.

It can be used as a pre-and post-emergence weed killer. The preemergence herbicide application method is different from the postemergence one.

Let’s see each method separately, what you have to do, and what other things you have to take into account when you use Tenacity.

As with any herbicide, it’s also important to follow all safety precautions and use appropriate protective gear for farmers when handling and applying Tenacity.

Preemergence application of Tenacity herbicide

  1. Apply Tenacity before weed seed germination.
  2. Use Tenacity at 4-8 fl. oz. per acre in at least 30 gallons of water per acre. You should not exceed 5 fl. oz. per acre in the case of perennial ryegrass or fine fescues. Also, do not exceed 4 fl. oz. per acre on St. Augustinegrass.
  3. Using application equipment for herbicides, spray the surface with Tenacity herbicide
  4. Allow the herbicide to dry in the next 3-4 hours and be absorbed.
  5. After it has dried, you can seed the surface treated with herbicide.

According to its label, when you use Tenacity as a preemergence application for weeds like crabgrass or foxtail, you can combine it with Barricade 65 WG, which is another preemergence herbicide. This mix offers higher weed control.

Postemergence application of Tenacity herbicide

  1. Apply Tenacity when the weeds are still young.
  2. Check the weather forecast. The weather forecast should not show rain in the next 48 hours after applying the herbicide.
  3. Use Tenacity at 4-8 fl. oz. per acre in at least 30 gallons of water per acre.
    For better herbicide effectiveness, you can mix it with a non-ionic surfactant. The non-ionic surfactant helps the herbicide to spread evenly and penetrate as well as possible on the surface of the weed.
  4. Spray the weeds using a herbicide applicator.
  5. Allow it to dry for the next 48 hours.
  6. If necessary, reapply the herbicide 2-3 weeks after the initial application.

Spot Application of Tenacity herbicide

If you want to apply the Tenacity herbicide only on a small surface, then you can add 1 teaspoon of Tenacity to 2 gallons of water for preemergence application. For post-emergence spot application, you can add 1 teaspoon of Tenacity to 2 gallons of water and 3 teaspoons of a non-ionic surfactant.

When is the best time to spray Tenacity herbicide?

The best time to apply Tenacity herbicide is on a dry spring or fall day when the temperature is between 65°F and 85°F. Also, the weather forecast should show no rain for at least 24-48 hours. Check the weather forecast, and if rain is announced, reschedule the herbicide application.

How often to apply Tenacity herbicide?

You can apply Tenacity herbicide up to two times per year for both pre-emergence and post-emergence control of weeds. The label also states to not apply more than 16 oz. of Tenacity per acre per year or per crop.

What does tenacity herbicide kill?

Tenacity herbicide kills a multitude of weeds without harming the surrounding grass species. You can use Tenacity herbicide to kill dandelions, clover, crabgrass, and many more.

Below you can find a table with all weeds killed by Tenacity herbicide:

Table 1. Table with all weeds killed by Tenacity herbicide
Common Name Scientific Name Preemergence *1 Postemergence *2
Barnyardgrass Echinochloa crusgalli Y Y
Bentgrass, Creeping Agrostis stolonifera Y Y
Bluegrass, Annual Poa annua Suppression N
Buckhorn Plantain Plantago lanceolata Y Y
Buttercup Ranunculus sardous – *3 Y
Carpetweed Mollugo verticillata Y Y
Chickweed, Common Stellaria media Y Y
Chickweed, Mouseear Cerastium vulgatum Y Y
Clover, Large Hop Trifolium aureum Y Y
Clover, White Trifolium repens Y Y
Crabgrass, Large Digitaria sanguinalis Y Y *4
Crabgrass, Smooth Digitaria ischaemum Y Y *4
Crabgrass, Southern Digitaria ciliaris Y Y *4
Curly dock Rumex crispus Y
Dandelion, Catsear Hypochoeris radicata Y
Dandelion, Common Taraxacum officinale Y
Florida Betony Stachys floridana Y
Florida Pusley Richardia scabra Y
Foxtail, Yellow Setaria glauca Y Y
Galinsoga Galinsoga ciliata Y Y
Goosegrass Eleusine indica Y *4
Ground Ivy Glechoma hederacea Y
Healall Prunella vulgaris Y
Henbit Lamium amplexicaule Y
Lambsquarters, Common Chenopodium album Y Y
Lawn Burweed Soliva sessilis Y
Lovegrass, Tufted Eragrostis pectinacea Y
Marestail Conyza canadensis Y
Nimblewill Muhlenbergia schreberi Y
Nutsedge, Yellow Cyperus esculentus Y
Oxalis Oxalis stricta Y
Pigweed, Redroot Amaranthus retroflexus Y Y
Pigweed, Smooth Amaranthus hybridus Y Y
Purslane, Common Portulaca oleracea Y Y
Shepherd’s purse Capsella bursa-pastoris Y Y
Smartweed, Pale Polygonum lapathifolium Y Y
Smartweed, Pennsylvania Polygonum pensylvanicum Y Y
Speedwell, Persian Veronica persica Y
Speedwell, Purslane Veronica peregrina Y
Sowthistle Sonchus oleraceus Y
Swinecress Coronopus didymus Y
Thistle, Canada Cirsium arvense Y
Verbena Verbena hastata Y
Wild Carrot Daucus carota Y Y
Wild Violet Viola pratincola Y
Windmillgrass Chloris verticillata Y

*1 For broad spectrum preemergence activity apply with a grass preemergence herbicide such as Barricade 65WG
Herbicide, except when used for weed control in new seedings.

*2 Weed control with postemergence applications require a second application after 2 to 3 weeks. Apply to young,
actively growing weeds with a NIS type surfactant.

*3 “–“ Not tested.

*4 For best postemergence control, apply to less than 4 tiller crabgrass and goosegrass.

Safety & warnings for tenacity herbicide

To keep you, those around you, and the environment safe, it is important to follow all safety precautions and warnings when using and applying Tenacity herbicide.

Here are the general safety guidelines that you must follow when handling Tenacity:

  • Always wear protective gear for spraying herbicides. Read our herbicide guide to see what the herbicide equipment should include.
  • Read and follow the label instructions carefully. Before starting, take the time to read the instructions on the label. Read the rates of application, the timing, as well as restrictions.
  • Use the herbicide properly so as not to harm the environment.
  • Do not make a larger herbicide quantity than you need. If you make more, then you must dispose of it responsibly and by following local regulations.
  • Do not mix the herbicide with other herbicides that are not indicated on the label. Mixing untested herbicides can be very dangerous and have a negative environmental impact.
  • Apply it using an herbicide applicator. Do not apply through any type of irrigation system.
  • Store it correctly somewhere where children and animals can’t reach it.

How to store Tenacity herbicide

You should store Tenacity herbicide in a cool, dry, and well-ventilated place. You can keep Tenacity herbicide in a container, even the original container that it comes in. The container is designed to withstand the chemical’s properties and prevent leakage or spills.

The container should be protected from direct sunlight, heat sources, and high temperatures. Moreover, the container must be in a place that is out of reach of children and pets. I would even recommend you label it with the appropriate information to be recognized by other adults.

Do not forget! The container in which you store Tenacity herbicide can no longer be used!

Is Tenacity herbicide safe for dogs and other pets?

No, Tenacity herbicide is not safe for dogs and other pets. It can actually be harmful if ingested by pets.

Tenacity herbicide must be stored in a place where pets cannot reach it.

Also, when spraying Tenacity herbicide, keep the dogs, cats, other pets, and animals away from the treated area until it is completely dried. This may take up to 8-10 hours depending on weather conditions. Do not allow pets to chew or eat grass, weeds, or plants that have been treated with Tenacity herbicide.

Do NOT apply to these plants

Tenacity herbicide should not be applied to certain sensitive plants, including vegetables, fruit plants, trees, non-target grasses such as ornamental grasses or native grasses, and flowers or ornamental plants.

Reasons why Tenacity herbicide may not work

It can happen that sometimes the Tenacity herbicide does not work and you do not see the effectiveness of its application at all.

Below I show you some reasons why it is possible that Tenacity herbicide may not work:

  1. You did not apply it correctly. Did you use the correct one specified on the label? Did you spray it at the right moment? Remember that the rate and timing are crucial for good results.
  2. You did not correctly identify the weeds. Tenacity is effective in controlling 48 weeds. If you use Tenacity for weeds that are not on the list, the weeds will not be affected. Use Tenacity herbicides only for the weeds it can control.
  3. The weather conditions were not favorable. If the temperature is too high or low, then the effect of the herbicide is affected. Moreover, the humidity must be low and the soil must be dry when you apply this herbicide. If the herbicide is sprayed when high humidity, it may not dry quickly enough to be absorbed by the weeds or grasses.
  4. You did not spray evenly or enough. If the herbicide is not applied evenly or if the coverage is insufficient, the weeds may not die.
  5. Be patient. Tenacity herbicide can take 1-3 weeks to show visible results on weeds and grasses.

Mix rate calculator for Tenacity herbicide

Tenacity herbicide FAQ

Who uses Tenacity herbicides?

Tenacity herbicide is used by homeowners, landscapers, turn professionals, and even farmers and other agricultural professionals. The purpose of using this herbicide is to kill all the weeds on certain surfaces such as residential lawns, sports fields, school grounds, golf courses, parks, and any other turf areas.

Can Tenacity Herbicide be mixed with other herbicides?

Yes, Tenacity herbicide can be mixed with other herbicides that have been tested by the manufacturer and that are quoted on the product label.

Tenacity has been tested and can be used in combination with the following herbicides:

  • Barricade 65WG Herbicide (prodiamine)
  • Vanquish (dicamba)
  • Turflon ester (triclopyr)
  • Spotlight (fluroxypyr)
  • Quicksilver (carfentrazone)
  • Basagran (bentazone)
  • Princep (simazine )
  • AAtrex (atrazine)

What herbicide can you use instead of Tenacity?

The herbicide you can use instead of Tenacity is Prime Source Meso 4SC Select. Prime Source Meso 4SC Select is an alternative to Tenacity herbicide that contains the same active ingredient as it. This alternative also works the same as Tenacity by inhibiting the weeds’ photosynthesis.

Does Tenacity herbicide kill trees?

Tenacity herbicide does not kill but can harm trees if applied directly to the tree or its foliage. The label of Tenacity states that the herbicide must not be used around or over trees and their roots.

For trees’ safety, avoid herbicide application over the top of the trees and their roots.

Where to buy Tenacity herbicide

You can buy Tenacity herbicide from various agricultural supply stores or online retailers. The Tenacity herbicide price is $75 for a bottle of 8 oz.

Or you can buy directly from amazon. You have the link below.

Tenacity herbicide for lawns (Tips and Very Useful Info)

Tenacity herbicide is one of the most popular selective herbicides. It is commonly used in lawns and turfgrasses. This herbicide targets the weeds species while minimizing the impact of surrounding grasses.

Tenacity herbicide is safe to be used at or prior to seeding on the following types of grasses species, including:

  • Kentucky bluegrass – 5-8 fl. oz.
  • Centipedegrass – 5-8 fl. oz.
  • Buffalograss – 5-8 fl. oz.
  • Tall fescue – 5-8 fl. oz.
  • Perennial ryegrass – 5 fl. oz.
  • Fine fescue (creeping red, chewing, and hard) – 5 fl. oz.
  • St. Augustinegrass (grown for sod) – 4 fl. oz.

But are there any grasses on which you should not use Tenacity? Tenacity herbicides should not be applied on bentgrass, Poa annua, kikuyugrass, zoysiagrass, seashore paspalum, and bermudagrass. All these grasses are sensitive to this selective herbicide.

Should you mow before applying Tenacity herbicide?

You should mow at least 2-3 days before or 2-3 days after applying Tenacity herbicide. The grass needs this time to recover from the mowing or to absorb the herbicide.

Freshly cut grass does not absorb the herbicide that well. If you cut the grass and apply the herbicide immediately, its effect is reduced. For a good result, mow the grass, and apply the Tenacity herbicide after 2-3 days.

After applying the Tenacity herbicide, the grass needs some time to process and absorb the herbicide. Mowing too close to the time of herbicide application can result in reduced herbicide efficacy.


Because the process of cutting the grass can remove the herbicide from the surface of the target weeds before being absorbed.

Does Tenacity work on crabgrass?

Yes, Tenacity herbicide works on crabgrass and other 48 weeds. Crabgrass is a weed that can be difficult to kill at times. However, Tenacity does a great job and provides good control of crabgrass. This herbicide inhibits the growth of crabgrass, leading to its death.

To work, Tenacity must be applied properly on crabgrass. There are two ways to apply Tenacity to crabgrass:

  • You can use a post-emergence application of Tenacity herbicide. It is more effective this way
  • You can use a pre-emergence application of Tenacity herbicide. In this case, it is recommended to combine Tenacity with another pre-emergence herbicide like Barricade 65WG.

What if it rains after applying Tenacity?

If it rains after applying the Tenacity herbicide, its effectiveness will be reduced. It is best to check the weather forecast when considering applying herbicide. Always apply the herbicide when there is no rain announced in the weather forecast within the next 48 hours after application. Usually, rain washes the herbicide off the surface of the weed before being absorbed properly.

If it rains immediately or a few hours after applying the herbicide, it is good to consider a second application of the herbicide. You can also wait and see if the effectiveness of the herbicide has been reduced by the rain or not and then reapply the herbicide if necessary.

Can you overseed after using Tenacity?

Yes, you can overseed after using Tenacity herbicide.

Only for Fine fescue seeds, you should wait four weeks after applying the herbicide.

Should you seed before or after Tenacity?

You can seed before and after the Tenacity application.

It is a pre-and post-emergence herbicide, and it can be applied safely to the types of lawns tested after seeding but also before that. It provides a pre-emergence but also post-emergence control of many types of weeds.

What time of day should you apply Tenacity?

You should apply Tenacity when the temperature is between 65 and 85°F. Also, the weather forecast should not show any rain for the next 48 hours.

I recommend applying the herbicide in the early morning or late evening. The cooler temperature of the morning and evening does not cause the herbicide to evaporate immediately but helps it stay on the weeds’ surface longer to be absorbed properly.

Should you water the grass after Tenacity?

There are two different scenarios when it comes to watering the grass after Tenacity.

  1. For post-emergence applications, you should avoid watering the grass at least 48 hours after Tenacity.
  2. For pre-emergence applications, you should water the grass after Tenacity with 0.15 inches of water in the following days after application. If it rains and those 0.15 inches of water have been reached, there is no need to water separately.

Do you need to pull weeds after Tenacity?

No, you do not need to pull weeds after Tenacity because the weed will not absorb the herbicide. Not having time to absorb the herbicide, the weed can appear again in the same place.

For good results, I suggest not pulling weeds. In this way, the weed absorbs the herbicide and is killed from the inside out.

However, this is also influenced by the level of infestation and the maturity of the weeds. If the surface is completely infested and the weeds are mature and large, it is possible that the herbicide will not eliminate them, and you will have to pull them by hand to remove them. However, you should wait a few weeks after applying the herbicide and see its effect before pulling them out by hand.

How long does it take for Tenacity herbicide to work?

Tenacity herbicide can take up to 2 to 3 weeks to show visible results that it worked. Factors such as temperature, moisture, type of plant, and the level of the infestation can influence the exact period.

But how do you know that Tenacity herbicide works? Well, this herbicide kills the weeds by blocking the photosynthesis process in the plant. The weed absorbs the herbicide through the leaves. The inhibition of this process causes the weeds to turn white and die.

Surfactant for Tenacity herbicide

The Tenacity herbicide is also on the list of herbicides for which you can use a surfactant. According to the manufacturer, you can use Tenacity herbicide with a non-ionic surfactant in post-emergence applications.

If you are not convinced that you need a surfactant for herbicides, then you can read about why to use a surfactant for herbicides in general. You will find out what the advantages are.

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About the author: Dani Martelli
Dani FarmerDB

My name is Dani and I am a farmer with 10 years of experience. I will share with you everything about farming from processes, tips, machines, and more. Farming for me is not just a job but a way of life. Keep reading ...

  1. The calculator is confusing. For 1,000 sq. ft. of Bluegrass is shows a mere 0.69 gallons. One can never spray 0.69 gallons over 1,000 square feet!!

    It would be better to use cc’s instead of ounces.

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