Yellow Nutsedge (Cyperus esculentus): Identification & Selective Herbicide Matrix
Quick Agronomic Summary
Halosulfuron-methyl 5% (SedgeHammer+) or Sulfosulfuron 75% (Certainty) selectively eradicates Yellow Nutsedge and suppresses underground tubers when applied between 65°F and 90°F.
- Diagnostic Marker 1: Stiff, waxy, pale chartreuse-green blades that grow twice as fast as surrounding turfgrass
- Diagnostic Marker 2: Distinctly triangular (3-sided) solid stem cross-section with leaves arranged in ranks of three
- Diagnostic Marker 3: Golden-brown bottle-brush seedheads and underground pea-sized tubers (nutlets) on rhizome tips
What kills Yellow Nutsedge without damaging lawn grass?
Halosulfuron-methyl 5% (SedgeHammer+) or Sulfosulfuron 75% (Certainty) selectively eradicates Yellow Nutsedge and suppresses underground tubers when applied between 65°F and 90°F.
Standard broadleaf weed killers (2,4-D) and crabgrass herbicides (Quinclorac) have zero effect on sedges. Halosulfuron inhibits the ALS enzyme system across all 8 cool-season and warm-season turf types, halting growth within 48 hours and causing complete necrosis in 14 to 21 days.
When is the best time to treat Yellow Nutsedge in lawns?
Apply Halosulfuron or Sulfosulfuron in early-to-mid summer (June through July) when Yellow Nutsedge has 3 to 8 leaves and soil temperatures are above 65°F, prior to underground tuber hardening.
Never hand-pull Yellow Nutsedge: mechanical pulling breaks the crown and activates 3 to 5 dormant basal bulbs along the rhizome chain. Wait at least 48 hours after mowing so shoots have sufficient leaf area to absorb the herbicide.
EPA-Registered Herbicides Labeled for Yellow Nutsedge
The table below compares all selective herbicides in our database that control Yellow Nutsedge, including active ingredient groups, application temperature limits (°F), and surfactant requirements.
| Brand Name & EPA Reg. | Active Ingredient & WSSA Group | Temp Window (°F) | Surfactant & Mixing Protocol | Where to Buy |
|---|---|---|---|---|
| Tenacity EPA Reg. 100-1267 |
Mesotrione 40% Group 27 (HPPD Inhibitor) |
55°F – 85°F Rainfast: 6h |
Always apply with Non-Ionic Surfactant (NIS) at 1 tsp (5 mL) per gallon of water for post-emergent applications. Causes temporary white bleaching on susceptible weeds and turf tips. | Check Price at DoMyOwn View on Amazon |
| SedgeHammer+ EPA Reg. 81880-24-10163 |
Halosulfuron-methyl 5% Group 2 (ALS Inhibitor / Sulfonylurea) |
60°F – 90°F Rainfast: 4h |
SedgeHammer+ single-scoop pouches already contain a built-in non-ionic surfactant. If using bulk SedgeHammer 75WG, add 2 tsp NIS per gallon. | Check Price at DoMyOwn View on Amazon |
| TZone SE EPA Reg. 2217-920 |
Triclopyr 7.72%, 2,4-D 29.36%, Dicamba 2.22%, Sulfentrazone 0.66% Group 4 + Group 14 (Pyridine Auxin + Phenoxy + PPO Inhibitor) |
50°F – 80°F Rainfast: 3h |
Do NOT mix with surfactant when temperatures exceed 75°F. In cool spring or fall conditions (55°F–70°F), 0.5 tsp NIS per gallon improves waxy leaf penetration on Wild Violet. | Check Price at DoMyOwn View on Amazon |
| Certainty Turf Herbicide EPA Reg. 59639-138 |
Sulfosulfuron 75% Group 2 (ALS Inhibitor / Sulfonylurea) |
60°F – 90°F Rainfast: 3h |
Mandatory Non-Ionic Surfactant (NIS) at 1 tsp (0.25% v/v) per gallon of water. Frequently tank-mixed with Celsius WG for complete southern weed control. | Check Price at DoMyOwn View on Amazon |
| Image Kills Nutsedge EPA Reg. 228-719 |
Imazaquin 3.3% Group 2 (ALS Inhibitor / Imidazolinone) |
65°F – 90°F Rainfast: 6h |
Ready-to-mix liquid formulation contains surfactant; additional NIS is not required for standard broadcast or spot treatments. | Check Price at DoMyOwn View on Amazon |
Turfgrass Compatibility Matrix for Yellow Nutsedge Herbicides
Always verify that your chosen herbicide is safe for your specific lawn grass before broadcast spraying:
| Herbicide | KBG | Tall Fescue | Ryegrass | Bermuda | St. Aug | Zoysia | Centipede | Bahia |
|---|---|---|---|---|---|---|---|---|
| Tenacity | SAFE | SAFE | SAFE | AVOID ACTIVELY GROWING | SOD PRODUCTION ONLY | DAMAGE RISK | SAFE | AVOID |
| SedgeHammer+ | SAFE | SAFE | SAFE | SAFE | SAFE | SAFE | SAFE | SAFE |
| TZone SE | SAFE | SAFE | SAFE | DAMAGE RISK | AVOID | SAFE | AVOID | AVOID |
| Certainty Turf Herbicide | AVOID | AVOID | AVOID | SAFE | SAFE | SAFE | SAFE | SAFE |
| Image Kills Nutsedge | AVOID | AVOID | AVOID | SAFE | SAFE | SAFE | SAFE | AVOID |
How to Distinguish Yellow Nutsedge from Lookalike Weeds
| Lookalike Species | Key Botanical & Diagnostic Difference |
|---|---|
| Purple Nutsedge | Purple Nutsedge has darker green blades with blunt boat-shaped tips and reddish-purple seedheads, whereas Yellow Nutsedge has long tapering needle-like leaf tips and golden-yellow spikes. |
| Green Kyllinga | Green Kyllinga stays low at mowing height with a sweet-smelling rhizome system and forms compact, round green button-like seedheads instead of tall spiky umbels. |