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
- Diquat dibromide
- Chemical class
- Bipyridylium; WSSA Group 22 Photosystem I electron diverter that interferes with photosynthesis in green tissue.[2][1]
- Mode of action
- WSSA Group 22: Photosystem I inhibitors (bipyridyliums)[2][1]
- Signal word
- Reward Landscape and Aquatic Herbicide: Caution[1]
Water-use waits after pond treatment
At the top floating-weed rate of 1.25 gallons per surface acre, wait 3 days before drinking the water or irrigating turf and landscape plants, and 5 days before irrigating food crops.[1]
Fishing and swimming have no waiting period at any rate, and livestock wait 1 day. Treat in bands from the shore outward so fish can move to untreated water; New York use requires a supplemental local-needs label.[1]
Yearly limits on land
Landscape and industrial use is capped at 0.5 lb of active ingredient per acre per application, three maximum-rate applications a year, and 1.5 lb per acre per year. Turf is limited to 1.0 lb per acre per year and never greens or tees.[1]
Where it is used
Cover the weed completely. Reward is a contact herbicide, so missed leaves survive; young, succulent, actively growing weeds respond best.[1]
It doesn't move through the plant, which is why the label allows it as a precise edging or pruning tool. Perennial or deep-rooted weeds often need a systemic herbicide added to the tank.[1]
Mix with clean water and avoid stirring up mud during pond work, since muddy water reduces control. Excessive rates on trim-and-edge jobs can stain concrete.[1]
In dormant bermudagrass lawns it can clear winter weeds such as annual bluegrass, henbit and little barley, but the bermudagrass must be fully dormant or it may be injured.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Reward Landscape and Aquatic Herbicide[1] | Syngenta Crop Protection, LLC | 100-1091 | 37.3% | liquid concentrate (2 lb diquat cation per gallon) | Caution |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Reward Landscape and Aquatic Herbicide | Landscape beds, lawns, golf courses, roadsides, trim-and-edge work along driveways, walks and fences, and pond edges | Emerged broadleaf and grassy weeds (non-selective; kills green tissue it contacts) | 0.75 fl oz product per gallon of water[1] That's 0.75 oz (22 mL) per gallon with a nonionic surfactant of at least 75% active ingredient. Broadcast use runs 1 to 2 pints per acre. |
| Reward Landscape and Aquatic Herbicide | Ponds, lakes, drainage ditches and other still or slow-moving water: floating and marginal weeds | Water lettuce, water hyacinth, duckweed, salvinia, pennywort | 0.5–1.25 gal product per surface acre[1] Add 16 to 32 oz per acre of an approved wetting agent. Duckweed takes 1 to 1.25 gallons per acre. Not for cattails. |
| Reward Landscape and Aquatic Herbicide | Ponds and lakes: submersed weeds | Hydrilla, watermilfoils, coontail, elodea, naiad, bladderwort, most pondweeds; suppression of Spirogyra and Pithophora algae | 0.5 gal product per acre-foot of water[1] A pond averaging 4 feet deep needs 2 gallons per surface acre. Re-treat as needed at 14- to 21-day intervals. |
Safety and environmental hazards
People
Signal word CAUTION: harmful if inhaled or swallowed and causes moderate eye irritation; long skin contact can cause burns. Handlers wear waterproof gloves and eye protection, and backpack users on lawns and landscapes also wear a NIOSH-approved particulate respirator.[1]
Pets
Keep unprotected people out of areas where drift may reach. On land, nobody enters treated areas until the spray dries. After pond treatment, livestock and domestic animals wait 1 day before drinking the water.[1]
Bees and pollinators
No bee toxicity statement appears, but the label notes the product is toxic to plants and can harm forage and habitat for pollinators next to treated sites if spray drifts.[1]
Fish and water
Toxic to aquatic invertebrates. Dead, decaying weeds use up oxygen and can suffocate fish, so treat no more than half a water body at a time and wait 7 days before treating the next section.[1]
Common questions
- Does diquat kill weeds down to the roots?
- No. The label says it does not translocate systemically and recommends a systemic tank-mix partner for perennial or deep-rooted weeds.[1]
- Can I swim in a pond after diquat?
- Yes. The water-use table lists no waiting period for swimming or fishing, though drinking and irrigation waits range from 1 to 5 days.[1]
- Is Reward sold for homeowners?
- No. The label states it is intended for commercial use, and backpack applications on lawns and landscapes require a fit-tested respirator.[1]
Sources
- U.S. EPA Pesticide Product Label System, “Reward Landscape and Aquatic Herbicide label, EPA Reg. No. 100-1091 (EPA-stamped, Sept. 29, 2025).” www3.epa.gov/pesticides/chem_search/ppls/000100-01091-20250929.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)