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
- Indaziflam
- Chemical class
- Alkylazine; WSSA Group 29 cellulose biosynthesis inhibitor.[2][1]
- Mode of action
- WSSA Group 29: Cellulose biosynthesis inhibitors (alkylazines)[2][1]
- Signal word
- Indaziflam 74SC (sold as Specticle FLO, Specticle O and Marengo): none required[1]
Not for cool-season lawns
Kentucky bluegrass, tall and fine fescue, perennial and annual ryegrass, bentgrass and Poa trivialis can be badly injured. The label says not to use it on those grasses unless thinning or removal is wanted.[1]
It also can't be used on warm-season turf overseeded with cool-season grass, on newly seeded turf, or on golf greens, tees and collars.[1]
Long waits before seeding
Because it stops seedlings and root growth, the label calls for months-long gaps. After 6 to 10 fl oz per acre, wait 8 to 14 months before seeding or sprigging, and seed wildflowers no sooner than 6 to 12 months.[1]
Where it is used
Water it in lightly after spraying so it moves into the soil before weeds germinate. Rain within a few days does the same job, but skip spraying when runoff-causing rain is forecast.[1]
For annual bluegrass, apply between August and November to match local germination. For young crabgrass at the 1- to 2-leaf stage, use at least 6 fl oz per acre.[1]
Pull back heavy mulch before spraying landscape beds, then replace it, and don't cultivate the soil afterward. Both reduce weed control.[1]
If it lands on sensitive grass by mistake, activated charcoal applied within several hours can deactivate it.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Indaziflam 74SC (sold as Specticle FLO, Specticle O and Marengo)[1] | Environmental Science U.S., LLC | 101563-146 | 7.4% | suspension concentrate | none |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Indaziflam 74SC (sold as Specticle FLO, Specticle O and Marengo) | Established warm-season turf: bermudagrass, zoysiagrass, buffalograss, bahiagrass, St. Augustinegrass, centipedegrass, seashore paspalum | Crabgrass, goosegrass, annual bluegrass, annual sedges and kyllinga, broadleaf weeds | 3–10 fl oz product per acre[1] A single application is 6 to 10 fl oz per acre; split programs use 3 to 9 fl oz per application. St. Augustinegrass and centipedegrass top out at 6 fl oz. No more than 18.5 fl oz per acre in 12 months. |
| Indaziflam 74SC (sold as Specticle FLO, Specticle O and Marengo) | Established landscape ornamentals and hedgerows | Annual grasses and broadleaf weeds from seed | 6–12 fl oz product per acre[1] Applied as a directed spray to the soil around plants, not over the top. A follow-up within 90 days is allowed if the 12-month total stays at or under 18.5 fl oz per acre. |
Safety and environmental hazards
People
The product has no signal word. Applicators wear long sleeves, long pants, shoes and socks, and unprotected people stay out of treated areas until the spray dries.[1]
Pets
For non-farm sites the label's rule is to keep unprotected persons out until sprays have dried; it has no separate pet statement.[1]
Bees and pollinators
The label carries no bee or pollinator warning. It is sprayed onto the soil and works on germinating seedlings.[1]
Fish and water
Toxic to fish, aquatic invertebrates and plants. It has a high potential to reach surface water through runoff for months, and may leach to groundwater in permeable soils.[1]
Common questions
- Does indaziflam kill existing weeds?
- Mostly no. It is a preemergence herbicide with some early postemergence activity on crabgrass, annual bluegrass and oxalis; tank-mix a postemergence herbicide for weeds already up.[1]
- Will indaziflam control nutsedge?
- Only annual sedges from seed. The label says it doesn't control yellow or purple nutsedge or other sedges growing from tubers.[1]
- Can I use Specticle on a fescue or bluegrass lawn?
- No. The label lists tall fescue, fine fescue and Kentucky bluegrass among turfgrasses it may injure unacceptably.[1]
Sources
- U.S. EPA Pesticide Product Label System, “Indaziflam 74SC (Specticle FLO) label, EPA Reg. No. 101563-146 (EPA-stamped, Apr. 2, 2019).” www3.epa.gov/pesticides/chem_search/ppls/000432-01518-20190402.pdf (accessed 2026-10-06). EPA's site files this label under the product's earlier registration number, 432-1518.
- 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)