How to Kill Broadleaf Plantain in Tall Fescue Without Hurting Your Lawn
Direct Agronomic Answer
To selectively kill Broadleaf Plantain in Tall Fescue without damaging your turf, apply Tenacity (Mesotrione 40%), SpeedZone Lawn Weed Killer (2,4-D 28.57%, Mecoprop-p 5.88%, Dicamba 1.71%, Carfentrazone-ethyl 0.62%) when air temperatures are between 55°F and 85°F.
Broadleaf plantain translocates synthetic auxins rapidly into its fibrous root system. For warm-season lawns like St. Augustine and Centipede, Celsius WG provides safe control.
1. Labeled Safe Herbicides That Kill Broadleaf Plantain in Tall Fescue
| Recommended Product | Active Ingredient & Group | Application Temp (°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 |
2. What NOT to Spray on Tall Fescue When Treating Broadleaf Plantain
Warning: Common Broadleaf Plantain Killers That Damage Tall Fescue
Many retail herbicides advertised for Broadleaf Plantain are formulated for different turf zones and will severely injure Tall Fescue:
- AVOID Celsius WG (Thiencarbazone-methyl 8.7%, Iodosulfuron-methyl-sodium 1.9%, Dicamba 57.4%): Rated 'avoid' on Tall Fescue — high risk of turf phytotoxicity or stunting.
3. Optimal Seasonal Timing & Temperature Thresholds
Spray in early fall (September to October) when plants are actively moving carbohydrates to root reserves.
Spring applications work well before flower spikes emerge. Aerating compacted soil prevents plantain re-establishment.
4. Diagnostic Checklist: Confirm It Is Broadleaf Plantain Before Spraying
- Large, oval to egg-shaped, wavy-margined leaves with 3 to 5 prominent parallel veins
- Dense basal rosette hugging the ground tightly
- Erect, leafless flower stalks with dense, cylinder-like spikes of tiny seeds
Not 100% sure? Use our AI Photo Weed Scanner or review the full Broadleaf Plantain Botanical Profile.