Dallisgrass (Paspalum dilatatum): Identification & Selective Herbicide Matrix
Quick Agronomic Summary
Topramezone (Pylex) + Triclopyr in cool-season turf or Celsius WG + Certainty in warm-season turf suppresses Dallisgrass.
- Diagnostic Marker 1: Large, coarse, circular bunches with a dead, hollowed-out center as clumps age
- Diagnostic Marker 2: Wide, coarse leaf blades with a prominent midrib and hair on lower leaf sheaths
- Diagnostic Marker 3: Seedhead consists of 3 to 5 alternating drooping branches with black, caterpillar-like hairs on seeds
What herbicide kills Dallisgrass without killing the lawn?
Topramezone (Pylex) + Triclopyr in cool-season turf or Celsius WG + Certainty in warm-season turf suppresses Dallisgrass.
Dallisgrass is a deep-rooted perennial bunchgrass that resists most selective herbicides. Multiple post-emergent applications are necessary to starve the deep rhizome system.
When to spray Dallisgrass?
Treat in late summer to early fall when plants are translocating carbohydrates to rhizomes.
A spot treatment in late spring followed by an autumn application yields the highest mortality.
EPA-Registered Herbicides Labeled for Dallisgrass
The table below compares all selective herbicides in our database that control Dallisgrass, 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 |
|---|---|---|---|---|
| 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 Dallisgrass Herbicides
Always verify that your chosen herbicide is safe for your specific lawn grass before broadcast spraying:
How to Distinguish Dallisgrass from Lookalike Weeds
| Lookalike Species | Key Botanical & Diagnostic Difference |
|---|---|
| Crabgrass | Crabgrass is an annual with smooth finger-like spikes; Dallisgrass is a perennial forming huge coarse mounds with distinctive black caterpillar-like dots on seedheads. |