Tenacity Weed Control
Tenacity is a selective turf herbicide by Syngenta, powered by mesotrione — a Group 27 HPPD inhibitor. It delivers both pre-emergent and post-emergent control of more than 46 grass and broadleaf weed species while remaining safe on labeled turfgrass.
Shop Tenacity Weed KillerTenacity Herbicide by Syngenta
Mesotrione-based selective herbicide — pre-emergent and post-emergent weed control for lawns, golf courses, and sports turf
Syngenta — Group 27 HPPD Inhibitor — Mesotrione 40%
Tenacity is a selective turf herbicide developed for effective pre-emergence and post-emergence control of a wide range of grass and broadleaf weeds. Built around mesotrione, a proven active ingredient inspired by a naturally occurring plant compound, Tenacity is designed for turf managers, lawn care professionals, and property owners who need dependable weed control without sacrificing the health of labeled turf species.
Backed by Syngenta, Tenacity has become a recognized solution for controlling difficult weeds in lawns, landscapes, sports turf, and golf course settings. Its flexibility, systemic movement within the plant, and ability to work both before and after weeds emerge make it a distinct option in turf weed management.
- Pre-emergent and post-emergent weed control
- Controls 46+ broadleaf and grassy weed species
- Safe on labeled turfgrass species (KBG, tall fescue, perennial rye, centipede)
- Can be applied at seeding on labeled species
- Selective systemic control — absorbed through roots, shoots, and leaves
- Rainfast within 1 hour of application
- EPA reduced-risk herbicide status
- Unique Group 27 mode of action for resistance management
Trusted Turf Control Backed by Syngenta
Tenacity is part of the Syngenta portfolio in the United States. Syngenta is a science-based global company focused on helping growers and land managers meet modern agricultural and turf challenges through crop protection, seeds, seed treatments, and agronomic innovation.
In the U.S., Syngenta supports a wide range of crops and use sites with products developed to improve performance, fight resistance, and help users get better results with fewer compromises. That same innovation-driven approach is reflected in Tenacity.
Rather than relying on older herbicide concepts alone, Tenacity was developed around a different mode of action and a different way of solving turf weed problems. The result is a herbicide that fits both established turf programs and seeding programs, giving users more flexibility during establishment and renovation.
Syngenta's commitment to innovation is reflected in Tenacity — a herbicide developed through observation, science, and field utility, and now widely recognized for selective turf weed control where timing, turf safety, and broad-spectrum performance all matter.
What Makes Tenacity Different
A Different Kind of Herbicide
Tenacity stands out because its active ingredient, mesotrione, is based on a naturally occurring compound associated with the bottlebrush plant (Callistemon citrinus). The discovery began when a Syngenta scientist observed reduced weed growth beneath bottlebrush plants and concluded that the plant was producing compounds that suppressed competing vegetation.
From that observation, mesotrione was synthesized and developed into a selective herbicide for turf use. This origin reflects the core idea behind Tenacity — advanced weed control inspired by natural chemistry and refined through scientific development.
Unique Mode of Action
As a Group 27 herbicide, Tenacity offers a different mechanism than most older turf herbicides. This can be important in resistance management and in broadening control options across turf management programs.
Its ability to be used at seeding, its systemic activity, and its effectiveness against difficult turf weeds such as crabgrass, bentgrass, goosegrass, and nimblewill make it a distinct tool for modern turf management.
How Tenacity Works
Tenacity's active ingredient inhibits an enzyme known as HPPD, which is essential to photosynthesis in susceptible plants. When this process is disrupted, the plant can no longer form protective carotenoids. Without those compounds, chlorophyll and cell membranes are damaged by light and normal photosynthetic by-products.
In practical terms, treated weeds begin to lose vigor shortly after application. Growth suppression starts early, while visible symptoms often include whitening or bleaching of the foliage, followed by tissue decline and plant death over the following weeks. Full control typically occurs within two to three weeks, though repeat applications may be needed for certain species.
Because Tenacity is absorbed through roots, shoots, and leaves, and then moved throughout the plant through both xylem and phloem, it works systemically rather than only on the surface. That internal movement is one of the key reasons it is effective on both emerging and established target weeds.
Absorption
Taken up through roots, shoots, and leaves — then translocated throughout the plant via xylem and phloem
Disruption
HPPD inhibition stops carotenoid production — chlorophyll is damaged, foliage turns white or bleached
Control
Tissue decline leads to full weed death within 2–3 weeks — repeat applications may be needed for stubborn species
What Tenacity Controls
Tenacity provides pre-emergence and post-emergence control of more than 46 grass and broadleaf weed species — one of the broadest spectrums among selective turf herbicides.
Additional species may also be referenced depending on label allowances, special labels, and local approvals. Always confirm specific use directions on the current EPA-approved label.
Ideal For
Key Product Advantages
Pre-Emergent & Post-Emergent Activity
Tenacity controls weeds before they emerge and after they are already growing. This dual-use profile simplifies weed management plans and expands the number of situations where the product can be used.
Selective Systemic Control
Designed to control target weeds while remaining safe on labeled turfgrass species when used as directed. Because it moves throughout susceptible plants, it is more than just a contact herbicide.
Useful at Seeding
Can be applied at or before seeding on labeled turf species — a major advantage in turf establishment, reseeding, and renovation programs. Seeding can be done the same day as application.
Broad Weed Spectrum
With activity on more than 46 grass and broadleaf weeds, Tenacity helps reduce reliance on multiple single-purpose products for comprehensive weed management.
Control of Difficult Grassy Weeds
Known for selectively controlling problematic turf weeds such as bentgrass, nimblewill, crabgrass, and goosegrass in many turf settings where other herbicides fall short.
Rainfast in 1 Hour
Tenacity is rainfast one hour after application, providing practical flexibility when weather conditions are uncertain and helping ensure consistent performance.
EPA Reduced-Risk Status
Received reduced-risk status from the EPA based on its unique mode of action, low use rates, and favorable toxicity profiles relative to many herbicides on the market.
Tank Mixing Flexibility
Can be tank mixed with Barricade, dicamba, carfentrazone, triclopyr, and other herbicides to broaden the weed control spectrum or improve performance.
Turfgrass Tolerance
Safe for Use On
- Kentucky bluegrass
- Tall fescue
- Perennial ryegrass
- Centipedegrass
- Fine fescue (less than 20% of seed mix)
Seeding can be done the same day as application for labeled species. Lower use rates are recommended on perennial ryegrass, fine fescue, and St. Augustinegrass.
Not Recommended For
- Zoysiagrass
- Hybrid bermudagrass
- Common bermudagrass
- Seashore paspalum
- Kikuyugrass
- Putting greens
Turf safety depends on following labeled species restrictions, rates, and application directions carefully.
Application Basics
Recommended Rate for Hand-Held / Backpack Sprayers
Tenacity
1 teaspoon per 2 gallons of water
Non-Ionic Surfactant
3 teaspoons per 2 gallons of water
The use of a non-ionic surfactant is especially important for post-emergence control of certain weeds because it improves coverage and uptake on the leaf surface. Larger weeds and tougher species may not respond adequately without it.
Application rates, intervals, turf species tolerance, and tank mix options all matter. Tenacity should always be used according to the current EPA-approved label and any applicable state-specific directions.
Repeat Applications
- •Clover, ground ivy, wild violet, crabgrass: second application 2–3 weeks after initial treatment
- •Bentgrass & nimblewill: 3 applications spaced 3 weeks apart
- •Reseeding for bentgrass/nimblewill control should be done at the time of the second application
Expected Results
- •Works best on young, actively growing weeds
- •Visible bleaching and decline after application
- •Full weed death within 2–3 weeks
- •Earlier intervention leads to better results
Customer Reviews
I will share my experience with this product since there is not a lot of scattered information regarding it, and I had to piece together information before using it. I have your typical Bluegrass, Fescue, Ryegrass lawn that is common here in the midwest. I noticed that my weed population kept increasing despite my endless efforts to eradicate them. It wasn't until I started to rake the lawn that I realized I have an intruder — nimbleweed and bentgrass creeping OVER the top of my existing lawn. Despite the price, I chose to use Tenacity and save the good grass. You have to be patient with this product, it does work, and despite it working slow, it is powerful stuff, so follow the directions since they are specific to the weed you are applying them to. After about 10 days you will start to see the nimbleweed and bentgrass dying back. A bonus to this product is you can overseed right after your very last application, and your new seedlings will not have to compete with weed seeds when trying to establish. My only regret is that I wish I would have found this stuff sooner!
I have been trying for some years to identify and control the undesirable lawn grass called nimblewill. The nimblewill has been slowly and consistently spreading and taking over my lawn for a number of years. It probably had taken about 20% of the lawn (about 0.7 acre lot). I thought it was pretty much hopeless. The Tenacity is expensive, $60 or so for 8 oz. But for the number of gallons it makes, it's really not that much more expensive than any other lawn herbicides. I walked around and sprayed all the visible nimblewill in various sections of the lawn 2 or 3 times during late June and early July. At least 3-4 days after spraying, the leaves start to turn white on the ends, then the whole upper grass leaf will turn white. It stops growing and eventually turns brown and dries up. Bottom line — with about half of a 8 oz bottle this summer I realistically expect I will kill at least 85-90% of a huge nimblewill infestation in a 0.7 acre lot.
My wife and I bought an old farm house 4 years ago that was literally weeds and some sort of grass. I spent 2 years getting rid of weeds, then overseeding. I found that I had both Nimblewill and Creeping Bentgrass. The only solution being offered on most sites was to use Roundup. I didn't find that to be a realistic solution. Finally I found a mention of Tenacity. Well, I can NOT tell you how happy I am with the results. Huge patches of my lawn turned white, making it VERY CLEAR which was desirable turf grass and which was not. At the same time, my turf type grasses stayed a solid green. Tenacity is both a pre and post emergent, which means it will keep the weeds down while you seed, as well as kill those that exist. The beauty of this product is that you can spray it directly on areas you just seeded. I used a total of 3 tsp. on 1 acre — not a hint of weeds or weedy grasses.
If you happened to stumble upon this, I highly commend your efforts. If you're anything like me, you probably spent hours searching for a solution to bentgrass without having to kill off your entire lawn. I was ecstatic to find Tenacity. The short version? The stuff works — and very well. But here are some tips: be prepared with patience because it's a slow, starving selective herbicide. Don't expect burn-off or RoundUp-like results in 24 hours. I found that three applications is best at 2-week intervals. Use a surfactant. Invest in a heavy rake or dethatching rake. Rake out the bentgrass before you apply and before repeat applications. Also note that this small 8 oz bottle will create something like 60 gallons of herbicide. That's around a buck per gallon — consider this to be a good long-run investment.
I have been using Tenacity now for around 6 straight years. It might not be the cheapest herbicide but it seems to work consistently every time. The package arrived as expected, it works well with other pre-emergents, and it doesn't harm my lawn. The volume you get from this bottle lasts me years with 4k sq/ft of lawn to treat.
My dad and I for years have been lamenting whatever it is that has been cursing our lawns with clumpy patches of thick-bladed nastiness. I've tried pre-emergent, post-emergent, and wide-spectrum grass killer to no avail. Nothing seemed to work. Then a coworker mentioned that he was using this, and it seemed to really work. After about a week, the crabgrass started changing colors. First white, then brown, then gone. Overall it took about 20 days for it to die entirely. It is recommended that you use a surfactant with this. This does not appear to work on any of the other weeds I have, clover in particular — so after I've fully recovered I'm still going to have to use something like Weed-b-Gon on those. Regular weeds are much easier to kill.
Safety and Worker Protection
Tenacity has a restricted-entry interval of 12 hours. All applicators, mixers, and loaders should follow required PPE guidelines.
- Restricted-entry interval: 12 hours after application
- Required PPE: long-sleeved shirt, long pants, shoes plus socks, chemical-resistant gloves
- Avoid contact with skin and eyes during mixing and application
- Do not apply to areas where food is grown or near water sources
- Store in a cool, dry place away from heat sources — keep out of reach of children and pets
Important: Tenacity should always be used exactly as directed on the current EPA-approved label. Use site restrictions, turf species tolerance, application intervals, surfactant requirements, and tank mix compatibility all affect performance and safety. Dispose of containers in accordance with local, state, and federal regulations.
Frequently Asked Questions
Tenacity is a selective herbicide designed for turfgrass weed control. It can be used for both pre-emergence and post-emergence control of a wide range of broadleaf and grass weeds in labeled turf settings, including lawns, landscapes, sports turf, and golf course areas.
Tenacity is part of the Syngenta portfolio in the United States. Syngenta is a global science-based company known for crop protection, seed technologies, and agronomic innovation across agriculture and turf management.
The active ingredient in Tenacity is mesotrione. It is a Group 27 herbicide based on a naturally occurring compound associated with the bottlebrush plant, Callistemon citrinus.
Tenacity works by inhibiting an enzyme called HPPD, which is essential to photosynthesis in susceptible plants. As a result, treated weeds lose their ability to produce protective pigments, which leads to bleaching, decline, and eventual death.
Tenacity offers both pre-emergence and post-emergence activity. That flexibility is one of its main advantages, since it can help prevent weed germination while also controlling weeds that are already actively growing.
Tenacity is labeled for control of more than 46 weed species. These include common turf weeds such as crabgrass, goosegrass, bentgrass, nimblewill, chickweed, clover, dandelion, ground ivy, henbit, yellow nutsedge, wild violet, oxalis, and Canada thistle.
Tenacity stands out because it combines a unique mode of action with selective systemic control and the ability to be used at seeding on labeled turf species. It is also known for controlling difficult grassy weeds such as bentgrass and nimblewill in certain turf types.
Yes. Tenacity can be applied at or before seeding on labeled turfgrass species. According to the provided guidance, seeding can be done the same day as application for labeled species, and applying close to seeding time may provide added weed control benefits during establishment.
Tenacity can be used on several labeled turfgrass species, including Kentucky bluegrass, tall fescue, perennial ryegrass, fine fescue in limited mixtures, centipedegrass, and certain other managed turf settings as directed on the label. Lower use rates are recommended for perennial ryegrass, fine fescue, and St. Augustinegrass.
Yes. Tenacity is not recommended for use on zoysiagrass, hybrid bermudagrass, common bermudagrass, seashore paspalum, or kikuyugrass. It is also not intended for use on putting greens.
After application, Tenacity is absorbed and moved throughout the plant. Weed growth is usually suppressed soon after treatment, while visible bleaching symptoms develop as photosynthesis is disrupted. Full weed death often occurs within two to three weeks, although repeat applications may be needed for certain species.
In some cases, yes. Certain weeds, especially clover, ground ivy, wild violet, and crabgrass, may require a second application two to three weeks after the first. For bentgrass and nimblewill, the label guidance recommends three applications spaced three weeks apart.
Tenacity is considered rainfast one hour after application. Rainfall or irrigation after that point should not significantly reduce product performance according to the provided information.
Yes. Tenacity can be tank mixed with several other herbicides, including Barricade, dicamba, carfentrazone, triclopyr, atrazine, simazine, s-metolachlor, and certain three-way phenoxy herbicides. Tank mixing should always follow the current label directions and compatibility guidance.
Tenacity was granted reduced-risk status by the EPA because of its unique mode of action, low use rates, and favorable toxicity and human health profiles compared with many herbicides already on the market. This status helped recognize its value as a newer and more targeted turf weed control solution.
Get Tenacity Weed Killer for Your Lawn
Tenacity is a selective turf herbicide from Syngenta designed for pre-emergence and post-emergence control of more than 46 grass and broadleaf weeds. Powered by mesotrione and inspired by a naturally occurring plant compound, it offers systemic control, flexible application timing, and strong utility in lawns, landscapes, sports turf, and golf course management.
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