Common Lambsquarters (Chenopodium album): Identification & Selective Herbicide Matrix
Quick Agronomic Summary
Standard 2,4-D or Dicamba mixtures (SpeedZone/Trimec) readily control Lambsquarters between 55°F and 85°F.
- Diagnostic Marker 1: Erect upright growth with triangular to diamond-shaped wavy leaves
- Diagnostic Marker 2: Whitish, mealy or powdery coating on younger leaves and shoot tips
- Diagnostic Marker 3: Dense, spike-like clusters of tiny inconspicuous green flowers at stem ends
What kills Lambsquarters in turf?
Standard 2,4-D or Dicamba mixtures (SpeedZone/Trimec) readily control Lambsquarters between 55°F and 85°F.
Regular mowing easily prevents Lambsquarters from reaching upright maturity in maintained turf.
When to spray Lambsquarters?
Spray in late spring when seedlings are 2 to 4 inches tall.
The mealy coating becomes thicker with age; adding surfactant enhances foliar absorption.
EPA-Registered Herbicides Labeled for Common Lambsquarters
The table below compares all selective herbicides in our database that control Common Lambsquarters, 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 |
| SpeedZone Lawn Weed Killer EPA Reg. 2217-833 |
2,4-D 28.57%, Mecoprop-p 5.88%, Dicamba 1.71%, Carfentrazone-ethyl 0.62% Group 4 + Group 14 (Synthetic Auxins + PPO Inhibitor) |
50°F – 85°F Rainfast: 3h |
Do NOT add surfactant. Adding NIS or MSO increases ester volatility and causes severe contact burn on desirable cool-season turf. | Check Price at DoMyOwn View on Amazon |
| Barricade 4FL (Prodiamine 65 WDG) EPA Reg. 100-1139 |
Prodiamine 40.7% (or 65% WDG) Group 3 (Microtubule Assembly Inhibitor / Dinitroaniline) |
45°F – 90°F Rainfast: 0h |
Pre-emergent soil barrier: do NOT use foliar surfactant. Must be watered in with 0.5 inches of irrigation or rainfall within 14 days of application to activate. | Check Price at DoMyOwn View on Amazon |
Turfgrass Compatibility Matrix for Common Lambsquarters 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 |
| SpeedZone Lawn Weed Killer | SAFE | SAFE | SAFE | SAFE | AVOID | SAFE | AVOID | SAFE |
| Barricade 4FL (Prodiamine 65 WDG) | SAFE | SAFE | SAFE | SAFE | SAFE | SAFE | SAFE | SAFE |
How to Distinguish Common Lambsquarters from Lookalike Weeds
| Lookalike Species | Key Botanical & Diagnostic Difference |
|---|---|
| Redroot Pigweed | Pigweed has rough hairy stems and a reddish lower taproot, while Lambsquarters has hairless stems with white mealy powder on leaf undersides. |