Poa annua, commonly known as annual bluegrass, is a cool-season grass that often becomes a troublesome weed in lawns, golf courses, and agricultural fields. Known for its ability to rapidly germinate and spread, Poa annua can be difficult to control once established.

Thankfully, there are several herbicides available that can help you manage and eliminate this persistent weed.

This guide will cover some of the best herbicides for controlling Poa annua, providing both pre-emergent and post-emergent options for effective treatment.

Best Herbicides for Poa Annua

1. Prograss (Fluazifop-P-Butyl)

Prograss is a selective post-emergent herbicide specifically designed for controlling grassy weeds like Poa annua. It works by inhibiting the weed’s ability to synthesize proteins necessary for its growth.

Prograss is effective in turfgrass settings, especially during the growing season when Poa annua is actively growing. It targets Poa annua without harming most desirable turfgrass species.

2. Tenacity (Mesotrione)

Tenacity is a selective herbicide that effectively targets Poa annua in both cool-season and warm-season turf. It works by disrupting the plant’s ability to produce chlorophyll, causing the weed to die.

Tenacity can be applied as both a pre-emergent and post-emergent herbicide. It is a great choice for controlling Poa annua in lawns and sports fields, and it won’t harm most turf species when used properly.

3. Drive XLR8 (Quinclorac)

Drive XLR8 is a post-emergent herbicide that provides effective control of Poa annua in both residential and commercial turf settings. It works by disrupting the plant’s growth and development.

Drive XLR8 is most effective when applied to young, actively growing Poa annua. It is also relatively safe on most warm-season turfgrasses, making it a popular choice for golf courses and lawns.

4. Certainty (Sulfosulfuron)

Certainty is a selective post-emergent herbicide that controls a variety of grassy weeds, including Poa annua. It works by inhibiting the weed’s ability to produce key enzymes necessary for its survival.

Certainty is especially effective in turfgrass systems. It can be used on both cool-season and warm-season grasses, and it offers selective control of Poa annua while minimizing damage to desirable turf.

5. Weed-B-Gon (2,4-D, Dicamba, Mecoprop-P)

Weed-B-Gon is a broad-spectrum herbicide that targets a variety of broadleaf and grassy weeds, including Poa annua. It works by disrupting the weed’s cell structure, causing it to die.

Weed-B-Gon is especially effective on young Poa annua, but take care to avoid using it around sensitive plants as it can damage non-target species.

6. Roundup (Glyphosate)

Roundup is a non-selective herbicide that can be used to kill Poa annua. It works by disrupting the plant’s ability to produce proteins, leading to its death.

Roundup is effective but should be used with caution as it will kill most plants it comes into contact with. Use it as a spot treatment for Poa annua, especially in areas where desirable plants are not present.

7. Barricade (Prodiamine)

Barricade is a pre-emergent herbicide that prevents Poa annua seeds from germinating. It creates a barrier in the soil that stops weed seeds from sprouting.

Applying Barricade before Poa annua germinates in early spring will prevent it from establishing in your lawn or garden. It is an effective strategy for long-term Poa annua control.

8. Preen Weed Preventer (Trifluralin)

Preen Weed Preventer is a pre-emergent herbicide that prevents Poa annua from germinating in garden beds and lawns. It forms a barrier that blocks weed seed growth.

Preen is an effective way to manage Poa annua and other common garden weeds. It’s easy to apply and works well for preventing the initial growth of weeds before they become a problem.

9. Spectracide Weed Stop (2,4-D, Mecoprop-P, Dicamba)

Spectracide Weed Stop is a post-emergent herbicide that effectively targets Poa annua as well as other broadleaf and grassy weeds.

Use Spectracide when Poa annua is actively growing. It is non-selective and should be applied carefully to avoid harming surrounding plants.

10. SpeedZone (Carfentrazone)

SpeedZone is a fast-acting post-emergent herbicide that targets Poa annua and other broadleaf weeds. It works by rapidly disrupting the cell membranes of the weeds, leading to quick desiccation.

SpeedZone is effective for spot treatment of Poa annua and can be used on established lawns without harming most turfgrass species.

Buyer’s Guide: Choosing the Best Herbicide for Poa Annua

When selecting an herbicide for Poa annua, consider the following:

1. Pre-emergent vs. Post-emergent

If you want to prevent Poa annua from germinating, pre-emergent herbicides like Barricade and Preen are ideal. For existing plants, use post-emergent herbicides like Prograss or Tenacity to eliminate the weed.

2. Selectivity

Some herbicides, such as Prograss and Tenacity, are selective and won’t harm desirable turfgrass, while others, like Roundup, are non-selective and should be applied carefully.

3. Turf Compatibility

Make sure the herbicide you choose is safe for your specific type of turf. Some products are suitable for both cool- and warm-season grasses, while others are more effective for specific turf types.

4. Application Timing

Apply pre-emergent herbicides before Poa annua seeds germinate in early spring. Post-emergent herbicides should be applied when the weed is actively growing for optimal control.

5. Environmental Impact

Always consider the environmental impact of the herbicide you choose. Some herbicides may pose risks to non-target plants and wildlife. Read and follow the label instructions carefully.

Best Herbicide for Poa Annua  FAQs

• What is the best time to apply herbicide for Poa annua? The best time to apply pre-emergent herbicides is in early spring, before Poa annua seeds germinate. Post-emergent herbicides should be applied when the weed is actively growing.
• Can I use these herbicides on my lawn? Yes, many of these herbicides are safe for most turfgrass species. Always read the label for compatibility with your specific grass type.
• Are there any natural ways to control Poa annua? Yes, some natural methods include mulching, proper lawn care, and overseeding with desirable grasses.
• How long does it take for herbicides to work? Post-emergent herbicides usually show results within 7-14 days, while pre-emergent herbicides prevent germination within a few weeks.
• Is Poa annua resistant to herbicides? Poa annua has shown resistance to some herbicides, but using the right products and rotating herbicides can help manage resistance.
• Can I use these herbicides on my garden? It depends on the product. Some herbicides are safe for gardens, while others may harm plants. Always check the label.
• How can I prevent Poa annua from spreading? Maintain healthy turf, overseed with desirable grass species, and apply pre-emergent herbicides to prevent the spread of Poa annua.

Conclusion

Effective control of Poa annua requires timely application and careful selection of herbicides. By using the right products at the right time, you can successfully manage this common weed and maintain healthy, attractive turf. Whether you opt for a pre-emergent like Barricade or a post-emergent like Prograss, choosing the best herbicide for Poa annua is key to a weed-free landscape.

For the best results, consult with a local lawn care professional to tailor the herbicide application to your specific needs and lawn conditions.