Corn Speedwell (Veronica arvensis): Identification & Selective Herbicide Matrix
Quick Agronomic Summary
Carfentrazone (SpeedZone) or Isoxaben (pre-emergent) controls Corn Speedwell between 45°F and 70°F.
- Diagnostic Marker 1: Tiny, upright hairy stems (2 to 6 inches) growing in dense early spring patches
- Diagnostic Marker 2: Lower leaves rounded with scalloped margins; upper leaves narrow and stalkless
- Diagnostic Marker 3: Tiny, sky-blue four-petaled flowers followed by heart-shaped two-lobed seed capsules
What kills Corn Speedwell in lawns?
Carfentrazone (SpeedZone) or Isoxaben (pre-emergent) controls Corn Speedwell between 45°F and 70°F.
Standard 2,4-D provides very poor control on Veronica species. SpeedZone with carfentrazone or Drive XLR8 burns down speedwell within days.
When to treat Corn Speedwell?
Treat in late winter or early spring before heart-shaped seed pods develop.
Fall pre-emergent application of Isoxaben prevents seeds from sprouting in October.
EPA-Registered Herbicides Labeled for Corn Speedwell
The table below compares all selective herbicides in our database that control Corn Speedwell, 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 |
| Pylex Herbicide EPA Reg. 7969-327 |
Topramezone 29.7% Group 27 (HPPD Inhibitor / Pyrazolone) |
55°F – 85°F Rainfast: 1h |
Must be applied with Methylated Seed Oil (MSO) at 1 to 1.5 tsp per gallon of water. Tank-mixing with Triclopyr Ester reduces white bleaching and speeds up Bermudagrass and Goosegrass mortality. | Check Price at DoMyOwn View on Amazon |
Turfgrass Compatibility Matrix for Corn Speedwell Herbicides
Always verify that your chosen herbicide is safe for your specific lawn grass before broadcast spraying:
How to Distinguish Corn Speedwell from Lookalike Weeds
| Lookalike Species | Key Botanical & Diagnostic Difference |
|---|---|
| Common Chickweed | Chickweed has white flowers with deeply split petals; Speedwell has vibrant sky-blue flowers and heart-shaped seed pods. |