Maintaining a lush, weed-free Bermuda grass lawn is no small feat, and one of the most effective ways to achieve this is through the use of pre-emergent herbicides. These products are designed to nip the weed problem in the bud, preventing weed seeds from germinating in the first place. In this guide, we’ll delve into the top pre-emergent options for Bermuda grass, including Barricade, Dimension, Pendimethalin, and Specticle Flo. We’ll also discuss special considerations if you plan to overseed with ryegrass.
The Essentials of Pre-Emergents
What Are Pre-Emergents?
Pre-emergent herbicides work by creating a chemical barrier in the soil that prevents weed seeds from sprouting. This preemptive action keeps your lawn looking its best.
Do Pre-Emergents Kill Weeds?
No, pre-emergent herbicides prevent weeds. Once the weed has germinated and sprouted, a pre-emergent won’t do anything except maybe slow root development. If you want to kill a weed after it’s emerged, use a post-emergent herbicide.
Top Choices for Bermuda Grass
- Barricade (Prodiamine): Known for its long-lasting control and effectiveness against a wide range of weeds.
- Specticle Flo (Indaziflam): Renowned for its long residual control and broad-spectrum weed prevention. It has been studied for pre and post control of annual bluegrass (poa annua).
Other Great Options
- Dimension (Dithiopyr): Excellent for not just preventing weeds but also for controlling early-stage crabgrass.
- Pendimethalin: Particularly effective against annual grasses and certain broadleaf weeds.
In a study, it was found that pendimethalin, oryzalin, and dithiopyr suppressed the quality of bermudagrass 8 to 16% more than oxadiazon and prodiamine. Indaziflam was not mentioned in the study.
Application Tips
- Wash-In Requirement: Pre-emergents need to be washed into the soil to activate. Therefore, they should only be applied with other products that also require washing in.
- Granular vs. Sprayable: These herbicides come in both granular and sprayable forms. The choice often depends on your equipment, but spraying is recommended for best coverage.
How To Apply Barricade (Spring)
In the spring, Barricade, active ingredient prodiamine, is a common choice. You can apply 0.83 oz per 1,000 square feet per year. You’ll want to put it down at 55 degree soil temps. Better yet, apply half before 55 degree soil and the other half after, for extended coverage.
| When | Quantity |
| 50 degree soil temps which is around end of Feb in Dallas-Fort Worth. | 0.3 oz per 1,000 square feet |
| 30-60 days later | 0.3 oz per 1,000 square feet |
| Optional: Summer application if you experience weeds | 0.2 oz per 1,000 square feet |
How To Apply Spec Flo (Fall)
In the fall, many choose Specticle Flo, active ingredient indaziflam, for its resilience against poa annua. I prefer to split mine into 3 applications. However, you can do 1, 2 or 3 apps in the fall based on the charts below. You’ll want to get it down before 70 degree soil temps in the fall as most winter weeds start germinating once soil temperatures are under 70 degrees. Poa annua for example will germinate once soil temperatures are under 67 degrees for 7 consecutive days.
Specticle Flo is expensive, so consider posting on TurfGrassForum.com to find people looking to split or group buy it. When you split it 4 ways, it is only $80 a person and will last you many years. If you have no luck, you can buy BioAdvanced 3-In-1, which is a weed and feed and not recommended, but does contain indaziflam, penoxsulam, and dicamba acid.
| When | Quantity |
| 80 degree soil temperature (maybe labor day in DFW) | 2 – 3 mL per 1,000 sqft |
| 30-45 days later (maybe mid October) | 2 – 3 mL per 1,000 sqft |
| 30-45 days later (maybe December 1st) | 2 – 3 mL per 1,000 sqft |
Special Considerations for Overseeding with Ryegrass
If you’re planning to overseed your Bermuda grass lawn with ryegrass for winter color, you may not be able to apply a fall pre-emergent. In addition to preventing weeds from germinating, these herbicides can also prevent the ryegrass seeds from germinating. With Specticle Flo, for example, you can’t apply it within 10 months of seeding.
Some pre-emergents are less inhibitory to ryegrass than others but many of those aren’t safe on Bermuda grass. Check the label for compatibility before application.
Conclusion
Pre-emergent herbicides are a powerful tool in maintaining a pristine Bermuda grass lawn. Whether you opt for Barricade, Dimension, Pendimethalin, or Specticle Flo, remember that these products need to be washed into the soil to be effective. And if you’re considering overseeding with ryegrass, make sure to time your pre-emergent application carefully to avoid inhibiting the ryegrass seed germination. With these tips in hand, you’re well on your way to a weed-free, beautiful lawn.
Leave a Reply