How Soon Can You Water After Applying Tenacity?

I have found that very few weed killers on the market can compete with a selective herbicide of Tenacity’s caliber. Tenacity, a word that means to be able to grip something firmly, surely accomplishes that as a weed killer that clings to undesirable weeds and inhibits photosynthesis. When I need a turf-safe and effective weed killer to help keep my lawn lush, this is the one I choose.

 But an herbicide is only effective with an accurate application, so reading the instructions is key, as is the proper application rate and timing of application. Most importantly, I will tell you how long before tenacity is rainproof, whether it needs to be watered in, and any other Tenacity questions you may have.

How Long Until Tenacity is Waterproof?

The application methods of herbicides vary greatly, and their effectiveness on plants is entirely dependent on you reading the labels and following the instructions exactly. I have tried to take shortcuts in the past, and the results have always been less than ideal and sometimes disastrous. 

One of the main things I messed up was I didn’t wait long enough before watering after applying an herbicide as a post-emergent. If you are using Tenacity for a post-emergent application, you need to wait at least two hours before allowing it to get wet. After 2 hours, it is safe for kids and pets, and rain or high temperatures will not affect its effectiveness. I told you it was a killer weed killer! 

How To Apply Tenacity?

Tenacity Turf Herbicide - 8 ounces

The technique you use to apply Tenacity depends entirely on why you are applying it. This selective weed killer works on more than 46 types of broadleaf weeds and invasive grasses found in lawns.

 Tenacity can also be used as a pre-emergent or a post-emergent weed killer. With so many variables that could cause problems, I figured I could help break down the different applications and make it easier for you. 

Emergent Application

 Tenacity can be used either before a weed has broken the surface (pre) or after a plant has grown (post). The method of each emergent application is slightly different.

  • Pre-Emergent:
    • Add 1 teaspoon of Tenacity to 2 gallons of water in a backpack sprayer.
    • Spray the area where your suspect weed germination will occur. 
    • Spread new turf seeds right after herbicide application. 
    • Allow up to 2 hours to dry and be absorbed.
  • Post-Emergent:
    • Add 1 teaspoon of Tenacity and 3 teaspoons of a good quality non-ionic surfactant to 2 gallons of water in a backpack sprayer. (optional turf coloring to prevent laying too much weedkiller)
    • Spray the area with target weeds thoroughly and try to achieve an even covering. 
    • Allow up to 2 hours to dry. 
    • Reapply 2-3 weeks after initial application if needed. 

Time of Application

In order for Tenacity to be effective, the timing of application must be correct. There are times when it would not be recommended to spray Tenacity, and there are conditions that will make it far less effective. The best time to apply Tenacity is on a dry day in the spring or fall. You are going to want to wait until a day when the temperature will not exceed 80°F for at least 2 hours after application. If you apply Tenacity like this, you will have the best results. 

Application Rate

Using the proper rate of application will make sure you kill all the weeds without damaging your turf. Even though Tenacity is a selective herbicide, too much too soon can still damage your turf. I have also found that spraying it when it is too hot or applying too heavy of a layer has resulted in non-target grasses turning white. The dilution rate is 1 teaspoon of Tenacity to 2 gallons of water. The maximum application rate is 4 to 8 fl oz per acre in at least 30 gallons of water. For post-emergent, add a nonionic surfactant. 

Common Weeds Controlled by Tenacity

On Sale
Syngenta Tenacity Herbicide – Pre-Emergent and Post-Emergent Weed Control, 8-oz. Liquid Weed Killer for Lawns and Turf Grasses, Active Ingredient…
  • BROAD-SPECTRUM WEED CONTROL: Tenacity herbicide is a liquid lawn weed control solution labeled to…
  • APPLICATIONS AT SEEDING: Unlike most herbicides, Tenacity can be applied anytime you are seeding,…
  • SELECTIVE PRE- AND POST-EMERGENT CONTROL: Based on a naturally occurring compound produced by the…
  • EASY TO MEASURE AND POUR: No more lost syringes. Simply squeeze the bottle to place the precise…

One of the major advantages Tencaity holds is that while it is safe for most lawn turf grasses, it is a nightmare for over 46 types of invasive plants. The two types of weeds Tenacity works best against are broadleaf weeds and grasses. Since these are the most common lawn invaders, this herbicide is ideal. Let’s look at some of the most common weeds this killer eliminates. 

Annual BluegrassButtercup
Smooth CrabgrassCarpetweed
Large CrabgrassLarge Hop Clover
Southern CrabgrassWhite Clover
Creeping BentgrassYellow Nutsedge
BarnyardgrassCommon Dandelion
Tufted LovegrassHenbit
GoosegrassCommon Purslane
WindmillgrassCanada Thistle

Tenacity FAQ

What Is Tenacity?

Tenacity is a selective herbicide that can be used as a pre or post-emergent. Its active ingredient is Mesotrione (40%), and it is derived from the bottlebrush plant (Callistemon citrinus). It targets broadleaf and invasive grasses but is safe for use on most turf grasses. Tenacity is a systematic herbicide and interacts differently with weeds than contact herbicides do.

How Does it Work?

Tenacity is a systematic herbicide that is absorbed by the target plant’s roots, shoots, and leaves. Once it has been absorbed by the plant, it is distributed throughout the plant’s system, effectively killing it from the inside out. Mesotrione inhibits a weed’s ability to photosynthesize, and without energy, the plants eventually wither and die. Effects can be noticed after a few days, but it may take up to 3 weeks to be completely effective.

Is It Safe?

Tenacity is considered pet and child safe. Once it has been applied to the lawn, allow up to 2 hours for it to dry. After two hours, it no longer will transfer to pets or children and has been fully absorbed by the weeds. 

Does Tenacity Herbicide Need to Be Watered in?

According to the label, this weed killer should be applied to a dry lawn. Irrigation and rain are acceptable after 2 hours of dry time. Tenacity herbicide does not need to be watered in.

How Long Until It Is Rainproof?

If tenacity is applied on a dry day with a temperature of less than 80°F, then it will be rainproof in just 2 hours. 

How Long Does It Last?

After Tenacity is mixed with water, it should be used within 24hrs. Any use after that time period will be less or possibly ineffectual against weeds. If it is stored in the original bottle and unmixed, then Tenacity can be kept and used for up to 5 years.

Last update on 2024-06-16 / Affiliate links / Somes Images and Data from Amazon Product Advertising API