Dollarweed (Pennywort) (Hydrocotyle umbellata): Identification & Selective Herbicide Matrix
Quick Agronomic Summary
Atrazine (Hi-Yield) or Celsius WG selectively kills Dollarweed in St. Augustine, Centipede, and Zoysia between 65°F and 90°F.
- Diagnostic Marker 1: Bright green, circular silver-dollar-shaped leaves with scalloped margins
- Diagnostic Marker 2: Petiole attaches directly in the center of the leaf undersurface (peltate umbrella-like)
- Diagnostic Marker 3: Spreading fleshy rhizomes and tubers thriving in over-irrigated waterlogged soil
What herbicide kills Dollarweed in St. Augustine and warm-season lawns?
Atrazine (Hi-Yield) or Celsius WG selectively kills Dollarweed in St. Augustine, Centipede, and Zoysia between 65°F and 90°F.
For Bermudagrass and cool-season turf, 2,4-D or SpeedZone is effective. Reducing irrigation frequency is vital as Dollarweed indicates waterlogged conditions.
When to spray Dollarweed?
Spray in spring or fall when Dollarweed is actively sending up new circular leaves.
Sequential applications 2 to 3 weeks apart are required to eradicate deep underground rhizomes.
EPA-Registered Herbicides Labeled for Dollarweed (Pennywort)
The table below compares all selective herbicides in our database that control Dollarweed (Pennywort), 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 |
|---|---|---|---|---|
| Drive XLR8 EPA Reg. 7969-272 |
Quinclorac 18.92% Group 4 (Synthetic Auxin / Quinoline Carboxylic Acid) |
60°F – 85°F Rainfast: 1h |
Requires Methylated Seed Oil (MSO) surfactant at 1.5 tbsp (0.75 fl oz) per gallon of water for effective cuticle penetration on multi-tiller crabgrass. | 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 |
| 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 |
| 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 |
| 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 Dollarweed (Pennywort) 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 |
|---|---|---|---|---|---|---|---|---|
| Drive XLR8 | SAFE | SAFE | SAFE | SAFE | AVOID | SAFE | AVOID | AVOID |
| SpeedZone Lawn Weed Killer | SAFE | SAFE | SAFE | SAFE | AVOID | SAFE | AVOID | SAFE |
| Celsius WG | AVOID | AVOID | AVOID | SAFE | SAFE | SAFE | SAFE | AVOID |
| Image Kills Nutsedge | 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 Dollarweed (Pennywort) from Lookalike Weeds
| Lookalike Species | Key Botanical & Diagnostic Difference |
|---|---|
| Dichondra | Dichondra has kidney-shaped leaves with petiole attached at the margin notch, while Dollarweed leaf stalk attaches directly dead-center under the leaf. |