The label is the law. Rates and restrictions below are taken from the product labels listed under Sources. Your product's own label governs; read it before you mix or apply. Mixing calculator · Disclaimer
- Active ingredient
- Sulfosulfuron
- Chemical class
- Sulfonylurea; WSSA Group 2 acetolactate synthase (ALS) inhibitor, which blocks production of the amino acids valine, leucine and isoleucine.[2][1]
- Mode of action
- WSSA Group 2: Acetolactate synthase (ALS) / AHAS inhibitors (sulfonylureas)[2][1]
- Signal word
- Certainty Turf Herbicide: Caution[1]
Turf tolerance and where it can't go
St. Augustinegrass and seashore paspalum may be more sensitive, so the label says to test a small area first. Temporary yellowing and delayed green-up can occur on warm-season turf.[1]
Don't apply on or within 4 feet of golf putting greens. It may not go through irrigation systems or by air, and the yearly total of all treatments can't exceed 2.66 oz per acre.[1]
Cool-season grasses
Perennial ryegrass, fine fescue and creeping bentgrass are more sensitive than Kentucky bluegrass, and over-application can thin or kill the stand. Apply only while cool-season turf is actively growing and needs mowing.[1]
Where it is used
Spray when weeds are actively growing, and skip mowing for at least 2 days before and 2 days after. Growth stops within 24 hours, but yellowing or browning takes 2 to 3 weeks to show.[1]
For hand-held sprayers the label uses a measuring scoop and 2 gallons of spray per 1,000 sq ft. One level small scoop in 2 gallons of water equals 0.25 oz per acre.[1]
Add a nonionic surfactant: 2 teaspoons per gallon in hand sprayers. Heavy rain or irrigation within 2 hours can wash it off the leaves.[1]
Clean sprayers right away with a 1% ammonia rinse, about 1 quart of ammonia per 25 gallons of water, done twice and followed by clean water.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Certainty Turf Herbicide[1] | Valent U.S.A. LLC | 59639-226 | 75.0% | water-dispersible granule | Caution |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Certainty Turf Herbicide | Warm-season turf: bermudagrass, bahiagrass, buffalograss, centipedegrass, kikuyugrass, St. Augustinegrass, seashore paspalum and zoysiagrass | Purple and yellow nutsedge, green and false green kyllinga, globe and annual sedges; tall fescue, Poa annua and listed broadleaf weeds | 1.25–2.0 oz product per acre[1] For sedges, 1.25 oz per acre once weeds have 3 to 8 leaves, with a repeat after 4 or more weeks if needed. No more than 2 applications and 2.5 oz per acre a year for sedges or tall fescue. |
| Certainty Turf Herbicide | Established Kentucky bluegrass and bluegrass mixes on non-residential turf | Nutsedges, kyllinga, roughstalk bluegrass, tall fescue and listed broadleaf weeds | 0.25–0.75 oz product per acre[1] 0.75 oz per acre in pure Kentucky bluegrass; 0.25 to 0.5 oz per acre where perennial ryegrass or fine fescue is mixed in. The cool-season section is not intended for residential turf. |
Safety and environmental hazards
People
Signal word CAUTION: causes moderate eye irritation. Applicators wear long sleeves, long pants, shoes and socks, and waterproof chemical-resistant gloves, then wash with soap and water after handling.[1]
Pets
Keep people and pets off treated areas until the spray solution has dried.[1]
Bees and pollinators
The label has no bee toxicity warning, but it says the herbicide may harm forage and habitat used by pollinators near the treated area, so keep drift down.[1]
Fish and water
The label carries a groundwater advisory for permeable soils with shallow water tables. It can reach ponds and streams in runoff for months, so avoid spraying when rain or irrigation is expected within 48 hours.[1]
Common questions
- Does sulfosulfuron kill nutsedge?
- Yes. Certainty lists purple and yellow nutsedge as controlled in warm-season turf at 1.25 oz per acre, applied at the 3- to 8-leaf stage.[1]
- Can Certainty remove tall fescue clumps from bermudagrass?
- Yes. The label's best tall fescue control in warm-season turf is 1.25 oz per acre followed by another 1.25 oz 21 to 28 days later, or one 2.0 oz application.[1]
- Can I use Certainty on a tall fescue lawn?
- No. Tall fescue is one of its target weeds. Its cool-season directions cover creeping bentgrass and Kentucky bluegrass stands, and they are not intended for residential turf.[1]
Sources
- U.S. EPA Pesticide Product Label System, “Certainty Turf Herbicide label, EPA Reg. No. 59639-226 (EPA-stamped, Nov. 7, 2024).” www3.epa.gov/pesticides/chem_search/ppls/059639-00226-20241107.pdf (accessed 2026-10-06)
- Weed Science Society of America, “Summary of Herbicide Mechanism of Action According to the Weed Science Society of America.” wssa.net/wp-content/uploads/WSSA-Mechanism-of-Action.pdf (accessed 2026-10-06)