Annual Bluegrass (Poa Annua) (Poa annua): Identification & Selective Herbicide Matrix
Quick Agronomic Summary
Certainty (Sulfosulfuron) or Revolver selectively eliminates Poa Annua in warm-season turf, while Ethofumesate or X趨 controls it in cool-season turf.
- Diagnostic Marker 1: Bright apple-green to lime-green clumps contrasting sharply with darker turf
- Diagnostic Marker 2: Soft, crinkled leaf blades near the base with distinctive boat-shaped tips
- Diagnostic Marker 3: Abundant, prolific whitish seedheads produced even at mowing heights under 0.5 inches
What herbicide selectively kills Poa Annua in lawns?
Certainty (Sulfosulfuron) or Revolver selectively eliminates Poa Annua in warm-season turf, while Ethofumesate or X趨 controls it in cool-season turf.
In cool-season lawns, Poa Annua is genetically related to Kentucky Bluegrass, making selective removal challenging. Pre-emergents (Prodiamine) in late summer prevent fall germination.
When to apply pre-emergent for Poa Annua?
Apply pre-emergent Prodiamine in late summer (late August to September) when soil temperatures drop to 70°F.
Post-emergent sprays in warm-season turf work best on young seedlings in November or February.
EPA-Registered Herbicides Labeled for Annual Bluegrass (Poa Annua)
The table below compares all selective herbicides in our database that control Annual Bluegrass (Poa Annua), 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 |
|---|---|---|---|---|
| Certainty Turf Herbicide EPA Reg. 59639-138 |
Sulfosulfuron 75% Group 2 (ALS Inhibitor / Sulfonylurea) |
60°F – 90°F Rainfast: 3h |
Mandatory Non-Ionic Surfactant (NIS) at 1 tsp (0.25% v/v) per gallon of water. Frequently tank-mixed with Celsius WG for complete southern weed control. | 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 |
| Barricade 4FL (Prodiamine 65 WDG) EPA Reg. 100-1139 |
Prodiamine 40.7% (or 65% WDG) Group 3 (Microtubule Assembly Inhibitor / Dinitroaniline) |
45°F – 90°F Rainfast: 0h |
Pre-emergent soil barrier: do NOT use foliar surfactant. Must be watered in with 0.5 inches of irrigation or rainfall within 14 days of application to activate. | Check Price at DoMyOwn View on Amazon |
Turfgrass Compatibility Matrix for Annual Bluegrass (Poa Annua) 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 |
|---|---|---|---|---|---|---|---|---|
| Certainty Turf Herbicide | AVOID | AVOID | AVOID | SAFE | SAFE | SAFE | SAFE | SAFE |
| 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 |
| Barricade 4FL (Prodiamine 65 WDG) | SAFE | SAFE | SAFE | SAFE | SAFE | SAFE | SAFE | SAFE |
How to Distinguish Annual Bluegrass (Poa Annua) from Lookalike Weeds
| Lookalike Species | Key Botanical & Diagnostic Difference |
|---|---|
| Kentucky Bluegrass | Kentucky Bluegrass is a dark blue-green perennial spreading by rhizomes; Poa Annua is lighter lime-green, bunches in annual tufts, and constantly produces seedheads. |