Tenacity is a systemic preemergence and postemergence herbicide for the selective contact and residual control of weeds in turfgrasses. When applied preemergence, weeds absorb Tenacity during emergence from the soil. Dry conditions following application may reduce the preemergence activity. If rainfall (0.15 inches) has not occurred within 10 days after a preemergence application, activate with 0.15 inches of irrigation. When used postemergence, susceptible weeds absorb Tenacity through foliar contact and soil absorption. Foliage of treated weeds cease growth after application, then turn white (loss of chlorophyll) and death may take up to three weeks. A repeat application is required after two to three weeks for improved postemergence weed control. A non-ionic surfactant should be added in postemergence applications.
|Active Ingredient:||Mesotrione 40%|
|For use in:||Kentucky Bluegrass, Centipedegrass, Buffalograss, Tall Fescue, Perennial Ryegrass, Fine Fescue, St. Augustine Grass|
|Coverage Area:||5 to 8 fluid ounces per acre|
What makes Tenacity different than other currently used turf herbicides?
Tenacity is a selective, systemic herbicide that features a new mode of action for pre- and post-emergence grass and broadleaf weed control in several cool- and warm-season turf species—like keeping bentgrass out of your rough. Tenacity can also be applied on established or newly seeded turf.
What is the active ingredient in Tenacity herbicide?
Mesotrione is the active ingredient in Tenacity herbicide.
How was Tenacity herbicide discovered?
A Syngenta scientist in California noticed that there were fewer weeds growing under his bottlebrush (Callistemon citrinus) plant, far fewer than can be explained by shading alone. He concluded that the plant must be producing allelochemicals to suppress weed competition. Syngenta synthesized mesotrione based on the allelochemicals produced by the bottlebrush plant.
What is the mode of action of Tenacity herbicide?
Tenacity inhibits a plant enzyme called HPPD that is essential to photosynthesis and prevents formation of carotenoids in susceptible plant species. Without carotenoids, light energy and by-products of photosynthesis will destroy chlorophyll and cell membranes. This results in bleaching of leaves followed by necrosis and death of the plant.
How quickly does Tenacity work?
Once absorbed, Tenacity quickly translocates throughout the plant. Weed growth is suppressed soon after application, as photosynthesis is disrupted. Death of the plant usually occurs within two to three weeks.
What turf species can Tenacity be applied to?
Tenacity can be applied to many of the cool-season turf types commonly found on fairways and roughs, such as Kentucky bluegrass, perennial ryegrass, tall fescue, fine fescue, centipedegrass, and St. Augustinegrass (sod only). Lower use rates are recommended for perennial ryegrass, fine fescue, and St. Augustinegrass. Tenacity is not for use on putting greens and tees.
What are some of the unique benefits of Tenacity herbicide?
Tenacity has pre- and post-emergence activity on 46 dicot and monocot weed species. It can selectively control perennial monocots such as bentgrass and nimblewill and annuals such as crabgrass and goosegrass in many turfgrass species. Tenacity can be applied at the seeding to prevent weed germination and allow the turfgrass species to establish without weed competition.
Can Tenacity be used to get bentgrass out of roughs and fairways?
Yes. Tenacity selectively controls bentgrass out of Kentucky bluegrass, perennial ryegrass, and tall fescue turf.
What does it mean that Tenacity was granted reduced-risk status by the EPA? Why did Tenacity earn this status?
Reduced-risk is an EPA designated registration status that accelerates the process for registration of certain new plant protection products. Tenacity received reduced-risk status by the EPA based on its unique mode of action, low use rates, and favorable toxicity and human health profiles, as compared to other herbicides currently on the market.
On which grasses has Tenacity been tested for use at or prior to seeding?
Tenacity is safe for use at or prior to seeding on Kentucky bluegrass, tall fescue, perennial ryegrass, and centipedegrass. Application at seeding can be made to fine fescue only if it is less than 20% of a seed mixture.
Are there any grasses on which you can't use Tenacity?
Tenacity is not recommended for use on zoysiagrass, hybrid or common bermudagrass, seashore paspalum, or kikuyugrass.
Can Tenacity be tank mixed with other herbicides?
Tenacity can be tank mixed with Barricade, dicamba, carfentrazone, triclorpyr, atrazine, simazine, s-metolachlor, bentazon, and several three-way phenoxy herbicides. Combinations can help turf managers broaden the weed control spectrum or improve the level of weed control over single-product applications.
How rainfast is Tenacity?
Tenacity is rainfast within several hours under normal rainfall conditions.
What other brands currently on the market offer a product similar to Tenacity?
There are currently no other herbicides like Tenacity for golf courses and sod farms registered for use or sale in the U.S. Tenacity will compete with multiple products from different classes of chemistry.
See all 33 reviews »
33 of 35 people found this review helpful:
By Frank on May 7, 2012
I had a lot of weed grasses in my yard and they were invasive and spreading over the whole yard. Tenacity targets weed grasses and kills them while leaving the rest of the yard in tact and that is exactly what it did. All of my weeds are dying. One thing you must note is that this herbicide needs to be watered after it dries on the plant so that the plant takes it in. It will not work if you just spray it on and don't get rain or water it for a couple of weeks. It's pricy but I know of no other chemical that will kill weed grasses and leave what you want, alone.
23 of 23 people found this review helpful:
A Miracle Herbicide!
By Margaret on August 14, 2012
I had a lawn that was completely taken over by bentgrass. I used round up on the lawn and put in an entire new lawn. All was well for a year or two. Then the the bentgrass came back in a few isolated areas. I would have to round them up at the end of the season and reseed. This went on for a number of years. When I learned about Tenacity I was thrilled and gave it a try. It works wonderfully! Yes it is pricy, however it beats having to round up the bentgrass, clear it out, put down more top soil and reseed. Try it...you won't be disappointed.
19 of 20 people found this review helpful:
Appears to be working!!!!!!!!!!!!
By Del on June 17, 2012
I was skeptical about whether Tenacity could kill the Nimblewill in my lawn and still leave my Blue Grass and Fescue alone. It's been 2 weeks since the first application and it appears to have definitely wounded the Nimblewill. The second application was applied yesterday, so we'll see if it kills it or not. It's a "pricey" chemical, but is easy to use and hopefully effective. If it works it sure beats Roundup and reseeding.
15 of 15 people found this review helpful:
No more Crabgrass!!
By Rob on August 23, 2012
This product really works. It does take time, so be patient. I still have to apply the second application to finish off the Crabgrass!!! It won't take much, the plants are almost dead now after 2 weeks.
14 of 17 people found this review helpful:
Great product! Does exactly what it advertises!
By Debi on September 7, 2012
My mom completely re-sodded front and back lawns and within 3 years it had been invaded by bentgrass. My new lawn was hydro-seeded 5 years ago in a new subdivision that used to be a golf course. Our methodology was to use Roundup in the fall (when the bent grass really seems to take off in growth) and then reseed the large killed off areas, hoping that the Roundup did a thorough job in killing the bentgrass. This becomes very tedious every year, not to mention the expense. We waited a few years for Tenacity to be available to the public and have both been having great results with the product. The good thing is that the remaining blades of good turf remain green in the kill zone. That gives me hope that I may not have to reseed, just wait for the good turf grass to fill in by itself. Our lawns are a combination kentucky blue and fescue blends. My only complaint is that the product is so concentrated and thick. The high concentration makes it even more critical to measure accurately! Not too crazy about the enclosed syringe measuring device. I feel it is too difficult to use and the potential to spill is high. I would love if there could be a more diluted Tenacity product to purchase for the average homeowner. That would make the product easier to measure, plus ensure a bit of wiggle room on the measurements?
1 of 1 people found this review helpful:
By Kathy on September 13, 2014
I purchased an 8 oz bottle of Tenacity to control the nimblewill that is beginning to take over my yard. I applied it according to instructions, and it has begun to show results after about i week.
0 of 2 people found this review helpful:
Only works temporarily
By Gary on September 10, 2014
It did work as advertised but the bentgrass came right back 100% in the same spots within 30 days. This product was applied professionally for two applications.
Tenacity for Chickweed
By Skip on September 9, 2014
I bought for Chickweed control and fall Chickweed pre-emergence. Will not see results until the Spring. On the plus side it has turned quite a few of the other weeds/grasses in my yard white. I just hope they die and do not come back. I used in a 2 gallon sprayer with non-ionic surfactant and a marking solution. Takes awhile to do the whole yard but well worth it if it controls the weeds and germination seeds better than the big store brands - Scxxts etc... I will re-apply in mid March and try for pre-emergence control of anything I might have missed.
So Far So Good
By Rick on September 8, 2014
I just put down my second application and so far I am very impressed. I'm putting it down with a 2 gal. tank sprayer. It has "done a number" on my bent grass and that is what I was primarily after. As a bonus, it is also wiping out my wild violets. I have been trying to kill those for about 10 years. I'm anxious to see what things look like in the spring. Has this really eliminated the patches of bent grass (and violets) or are they coming back in the spring?!?
Works as advertized
By Jerry on August 26, 2014
I used this product 4 weeks ago to some of my problem areas as far as crabgrass, creeping charlie and nutgrass. It did the job! Make sure you follow the directions as far as the 1 teaspoon per two gallons though. My first batch I did not measure and it took awhile for the grass to bounce back. Definitely turns the weeds white but don't worry it bounces back.
This is an incredible herbicide
By Barry on August 23, 2014
I applied this a week ago to creeping bent-grass and an occasional clump of crabgrass. As promised, the grasses are turning white. I'm sorely tempted to reapply after a week but will wait one more for the second application. And for those who note how expensive this is, it's a dollar an application for 2 gallons of spray ... compare that with other herbicides.. and it's low toxicity makes it a winner...
1 of 1 people found this review helpful:
Just what i needed
By Gerald on August 4, 2014
Tenacity did it's job for my lawn. I put down 2 applications and I am going to spot treat a few spots that I want to make sure my bent grass is gone. The grass is already growing in the areas where the bent grass has died, and my lawn only look bad for about 4 weeks. It now is the best looking on my block and is thick and dark green. I also sprayed it on my neighbor's crabgrass along the edge's were are yards meet, and it killed it in 2 weeks and is gone. Amazing stuff. I have not seen one weed in my yard since putting this tenacity on. Now I have areal big challenge coming up with my brothers yard going to use it on his, that will really tell me how well it kills weeds and other grasses.
1 of 1 people found this review helpful:
By Rcg270 on July 24, 2014
Bentgrass began turning white and Nutgrass brown a week after the first application. Read the directions for applying, must be water in after applying. Costly, but for the small amount you mix with water an 8oz bottle will last a long time.
By B on July 22, 2014
Product appears to be a little pricy; however, the dosage amount needed makes it cheaper than products from the box stores and this product works better. The only draw back on this product is you have to be patient to start seeing results which I've experienced is about a week.
1 of 1 people found this review helpful:
By R on July 8, 2014
Don't let the small container size fool you - a little bit goes a long way. It needs a non-ionic surfactant to be mixed with it, so be sure to order some when you order this product. It works by stopping chlorophyll production in the plant, so as the target starts to die, it turns white and your lawn looks unusual for a while. The fact is - this herbicide works on some tough to eradicate plants. It takes two applications.
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August 9, 2011
William from Springfield, Il. asked:
QHow much Tenacity do you mix in a one gallon sprayer?
October 11, 2011
Mary from Marshfield, Wi asked:
QDo I need to keep the dogs away from the area where I have applied Tenacity?
AYou should keep the dogs off of the area while you are applying Tenacity and until the area has had a chance to dry, about 2-4 hours.
June 14, 2013
Gregg from Hastings Ne asked:
QApplication tips for Tenacity
I wish to apply Tenacity with a hand sprayer. Do you have any application tips? Would broadcast application be better than spot spraying? If spot spraying, how much should I apply?
A According to the Tenacity product label for smaller applications you will need to mix 0.5 tsp of Tenacity, 1.5 tsp of surfactant to one gallon of water and each gallon of solution needs to cover 1,000 sq ft. Broadcast treatments would be recommended if you are needing to actually treat the entire lawn for pre-emergence, if you are only needing to treat small areas or use as a post emergent then you can spot treat.
According to the Tenacity product label for smaller applications you will need to mix 0.5 tsp of Tenacity, 1.5 tsp of surfactant to one gallon of water and each gallon of solution needs to cover 1,000 sq ft.
Broadcast treatments would be recommended if you are needing to actually treat the entire lawn for pre-emergence, if you are only needing to treat small areas or use as a post emergent then you can spot treat.
March 8, 2012
Scott from Grosse Ile Michigan asked:
QAfter applying Tenacity and surfactant how long do you have to wait to seed or sod?
AAccording to the Tenacity product label "Apply Tenacity at 5-8 fl. oz. per acre in at least 30 gallons of water per acre prior to seeding or post seeding of tolerant turfgrass species listed on this label, except fine fescue. Tenacity may reduce density of fine fescue seedings. Tenacity can be used on grass seed blends that contain less than 20% by weight of hard or fine fescue. Tenacity will control many monocot and dicot weeds that compete with and slow the establishment of the turfgrass stands. Apply at grass seeding or close to seeding for best performance. Avoid spraying on newly germinated turfgrass plants. Wait until the newly germinated turf has been mowed two times or four weeks after emergence (whichever is longer) before making a postemergence application." If you need more specific information on a turfgrass not mentioned on the product label you can reach the manufacturer at 866-796-4368.
January 15, 2012
Lea from Melbourne, Victoria, Australia asked:
QCould you please confirm that Tenacity will not kill of Tall Fescue or any other grasses?
Is Tenacity available in Australia, Melbourne
A Tenacity Herbicide is labeled for use on Tall Fescue, Kentucky Bluegrass, Centipedegrass, Buffalograss, Perennial Ryegrass, Fine Fescue, St. Augustine Grass. Other species of grass such as Bentgrass, Poa annua, kikuyugrass, zoysiagrass, seashore paspalum and bermudagrass are sensitive to Tenacity applications and damage may occur. According to the product label - Residential Lawn Applications: Unless renovating and/or re-seeding the home lawn, avoid broadcast applications of Tenacity for pre and post-emergence weed control because undesirable whitening of some turfgrasses may occur. We do not ship to Australia and we are not sure if the manufacturer offers Tenacity in Australia. You can contact the manufacturer, Syngenta, to inquire about availability 866-796-4368.
Tenacity Herbicide is labeled for use on Tall Fescue, Kentucky Bluegrass, Centipedegrass, Buffalograss, Perennial Ryegrass, Fine Fescue, St. Augustine Grass. Other species of grass such as Bentgrass, Poa annua, kikuyugrass, zoysiagrass, seashore paspalum and bermudagrass are sensitive to Tenacity applications and damage may occur. According to the product label - Residential Lawn Applications: Unless renovating and/or re-seeding the home lawn, avoid broadcast applications of Tenacity for pre and post-emergence weed control because undesirable whitening of some turfgrasses may occur.
We do not ship to Australia and we are not sure if the manufacturer offers Tenacity in Australia. You can contact the manufacturer, Syngenta, to inquire about availability 866-796-4368.
May 19, 2014
Keith from Delavan Wi asked:
QWill Tenacity kill creeping charlie?
Tenacity is labeled to control Ground Ivy "Creeping Charlie" as post emergent control. We highly recommend using a temporary turf colorant like Turf Mark Blue so that you can see where you spray with the Tenacity to avoid overlapping. Tenacity is a great product, but also a very strong product so too much overlapping or mixing the product too strong can cause temporary damage and whitening to your turf around the ground ivy. The color will come back in the lawn after 3-4 weeks but to avoid this potential problem it is best to use a colorant to make sure no overlap occurs. To get optimum results for post emergent control it is recommended you use a Non Ionic Surfactant in your mixture as well. Please make sure that you check the label to verify that it is safe for your type of turfgrass as you did not indicate the kind of lawn you will be applying the product to. Please let us know if you have any questions.
May 10, 2014
Emilia from Ann Arbor, Michigan asked:
QCan Tenacity Herbicide kill poison ivy/oak/sumac?
Tenacity Herbicide will no kill poison oak. Please see Bonide Poison Oak and Ivy Killer. Which is designed just for poison oan and ivy.
May 8, 2014
Scott from Saint Joseph, Michigan asked:
QHow do I get rid of Bermuda Grass in my yard?
I bought Tenacity from your company hoping it would do the trick. We have Kentucky Blue Grass and we live in Michigan. Maybe it's to soon to tell since I applied two applications in the last two weeks.
A The product label states that Bermuda grass is sensative to Tenacity. It may take more than one treatment to treat Bermuda grass. Also, the grasses and weeds you are treating for need to be activley growing with temps consistently above 55 degrees.
May 6, 2014
Anne from Horsham, Pennsylvania asked:
QIs it possible to apply Tenacity to a large area (one acre) with a hose-end sprayer?
A It is not recommended to use herbicides in hose end sprayers. The problem with using the hose end sprayer for the Tenacity Herbicide application is that they are not very accurate and you can wind up dispensing more/less product than needed in a given area which can lead to less than desirable results.
April 21, 2014
Mike from Groton, Ma asked:
QIs it possible to use a hose end sprayer to apply Tenacity?
Tenacity should not be applied with a hose end applicator. Tenacity if not applied evenly across the yard can temporarily whiten your lawn and cause you to not see full control of the weeds you want to eliminate. Also most hose end sprayers will not dial down to the small amounts needed per 1000 sq/ft that the Tenacity requires. Tenacity is best applied with some form of a pump/tank sprayer in even strokes without excess overlapping.
April 15, 2014
Chris from Colorado Springs, Co asked:
QWill Tenacity harm daylily?
March 10, 2014
Thomas from Cut Off, La. asked:
QWill Tenacity work on Dallisgrass?
A Per the product label, dallisgrass is sensitive to Tenacity. You should avoid spraying these turf areas. Please let us know if you are trying to get rid of dallisgrass or you are wanting to treat other weeds in dallisgrass. We would be happy to select a product that will fit your specific needs. For free expert advice, please call us at toll-free 866.581.7378 M-F 9-5PM EST.
March 10, 2014
Thomas from Cut Off, La. asked:
QWhat is the shelf life of Tenacity?
A The shelf life on most liquid herbicides all depends on how they are stored. If the product has been tightly sealed and kept out of sunlight and extreme temperatures, the shelf life is 3-5 years.
October 30, 2013
Sylvia from Belleville, Illinois asked:
QBest times to apply Tenacity for zone 6b
I want to use Tenacity for Nimblewill as a broadband post emergent now and later as a pre emergent to control re-infestation. Right now it is brown/tan in color in my lawn. Is it too late in the growing season to use it now?
Broadcast treatments would be recommended if you are needing to actually treat the entire lawn for pre-emergence, if you are only needing to treat small areas or use as a post emergent then you can spot treat. Consult your local Cooperative Extension Service for more specific applications timings for your local area. Their contact information can be found by clicking the link below. http://www.ahs.org/gardening-resources/master-gardeners http://www.csrees.usda.gov/index.html
Broadcast treatments would be recommended if you are needing to actually treat the entire lawn for pre-emergence, if you are only needing to treat small areas or use as a post emergent then you can spot treat. Consult your local Cooperative Extension Service for more specific applications timings for your local area. Their contact information can be found by clicking the link below.
October 10, 2013
Rick from Louisville, Ky asked:
QI'm confused whether or not it will hurt new Kentucky Bluegrass seed?
I've read the label but it say's it hurts Fescue's when seeding but it also says it suppresses Bluegrass, Annual Poa annua. I need this cleared up as I'm about to seed. I've already put 1 app of Tenacity down.