Yellow Woodsorrel (Oxalis) (Oxalis stricta): Identification & Selective Herbicide Matrix
Quick Agronomic Summary
Triclopyr (TZone SE) in cool-season lawns or Fluroxypyr/Celsius WG in warm-season lawns eradicates Oxalis between 55°F and 85°F.
- Diagnostic Marker 1: Pale green trifoliate leaves with distinct heart-shaped, deeply notched leaflets
- Diagnostic Marker 2: Leaves fold downward along the center crease at night or in intense heat
- Diagnostic Marker 3: Bright yellow 5-petaled flowers followed by upright, okra-like explosive seed capsules
What herbicide kills Oxalis in grass?
Triclopyr (TZone SE) in cool-season lawns or Fluroxypyr/Celsius WG in warm-season lawns eradicates Oxalis between 55°F and 85°F.
Standard 2,4-D fails on Oxalis. Systemic Triclopyr or Mesotrione provides excellent foliar and crown kill.
When to spray Oxalis?
Spray in spring or early summer before the explosive cylindrical seed pods mature.
Once seed pods form, slightest contact shoots seeds up to 10 feet into surrounding turf.
EPA-Registered Herbicides Labeled for Yellow Woodsorrel (Oxalis)
The table below compares all selective herbicides in our database that control Yellow Woodsorrel (Oxalis), 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 |
| 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 |
| Celsius WG EPA Reg. 432-1507 |
Thiencarbazone-methyl 8.7%, Iodosulfuron-methyl-sodium 1.9%, Dicamba 57.4% Group 2 + Group 4 (ALS Inhibitors + Benzoic Acid Auxin) |
65°F – 95°F Rainfast: 4h |
Apply with Non-Ionic Surfactant (NIS) at 1 tsp per gallon of water. Specifically engineered not to stunt warm-season turf during summer heat up to 95°F. | Check Price at DoMyOwn View on Amazon |
| Hi-Yield Atrazine Weed Killer EPA Reg. 34911-15-7401 |
Atrazine 40.8% Group 5 (Photosystem II Inhibitor / Triazine) |
50°F – 85°F Rainfast: 6h |
Do NOT add surfactant when spraying actively growing St. Augustine or Centipede above 80°F to avoid foliar yellowing. Irrigate lightly within 48 hours for root uptake. | Check Price at DoMyOwn View on Amazon |
Turfgrass Compatibility Matrix for Yellow Woodsorrel (Oxalis) 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 |
| TZone SE | SAFE | SAFE | SAFE | DAMAGE RISK | AVOID | SAFE | AVOID | AVOID |
| Celsius WG | AVOID | AVOID | AVOID | SAFE | SAFE | SAFE | SAFE | AVOID |
| Hi-Yield Atrazine Weed Killer | AVOID | AVOID | AVOID | DORMANT ONLY | SAFE | SAFE | SAFE | AVOID |
How to Distinguish Yellow Woodsorrel (Oxalis) from Lookalike Weeds
| Lookalike Species | Key Botanical & Diagnostic Difference |
|---|---|
| White Clover | Oxalis has heart-shaped notched leaflets and yellow flowers, while White Clover has round oval leaflets with faint white crescents and white flowers. |