Choosing the right weed killer for St Augustine grass can protect your turf from broadleaf and grassy weeds while preserving your lawn’s health. The products below are formulated for St Augustine and Floratam varieties, offering selective control and, in some cases, preventive benefits. This guide compares key options, helping homeowners select products that fit their lawn care goals and seasonal needs.
| Product | Brand | Use | Notes |
|---|---|---|---|
| Southern Ag Atrazine St. Augustine Grass Weed Killer, 1 Gallon | Southern Ag | Weed control in St Augustine and centipede grasses | Kills many broadleaf weeds; provides suppression of crabgrass |
| Southern Ag 006130 Atrazine St. Augustine Weed Killer 32oz | Southern Ag | Weed control in St Augustine and centipede grasses | Treats up to 3,720 sq ft; lightweight formulation |
| Scotts Turf Builder Southern Triple Action | Scotts | Weed killer, fire ant preventer, lawn fertilizer | 6 months of fire ant prevention; supports heat/drought tolerance |
| Hi-Yield Atrazine Weed Killer RTS (32 oz) | Hi-Yield | Atrazine-based weed control | Controls Poa annua and other common weeds in St Augustine and centipede grass |
| BioAdvanced 3-in-1 Weed and Feed for Southern Lawns | BioAdvanced | Weed killer and lawn fertilizer for Southern lawns | Up to 6 months of weed prevention; targets listed broadleaf weeds |
Note: Tables summarize product purpose and key points. Always follow label directions for application rates and timing to protect St Augustine lawns and nearby ornamental plants.
Southern Ag Atrazine St. Augustine Grass Weed Killer, 1 Gallon
Brand: Southern Ag. This atrazine-based formula targets a broad range of weeds common in St Augustine lawns and can also be used in centipede grass. It provides suppression of crabgrass and helps maintain dense turf when used as part of an integrated lawn care routine. Application guidelines emphasize uniform coverage and avoiding sensitive plants nearby. Consider compatibility with existing fertilizers to prevent nutrient-weed interactions and ensure even uptake by the lawn.
Southern Ag 006130 Atrazine St. Augustine Weed Killer 32oz
Brand: Southern Ag. This 32-ounce bottle treats up to several thousand square feet and is designed specifically for St Augustine and centipede grasses. It provides effective control of many common lawn weeds while fitting into standard residential spray equipment. The product’s compatibility with existing lawn care programs should be checked to avoid over-application and potential turf stress.
Scotts Turf Builder Southern Triple Action
Brand: Scotts. This is a 3-in-1 formula designed for Southern grass types, including St Augustine. It kills listed weeds, prevents and kills fire ants, and feeds to strengthen the lawn for heat and drought. It claims up to 6 months of fire ant prevention and also targets pests like armyworms and ticks. Suitable for St Augustinegrass, Floratam varieties, centipedegrass, and related southern lawns. Follow label directions for safe integration with fertilization schedules.
Hi-Yield Atrazine Weed Killer RTS (32 oz)
Brand: VPG (Hi-Yield). This atrazine-based RTS formulation targets annual bluegrass (Poa annua) and clover among other common weeds. It is intended for use on St Augustine and centipede grass, offering selective control that helps preserve desirable turf. Users should apply when target weeds are actively growing and avoid applying during extreme heat or drought stress to minimize turf injury and maximize efficacy.
BioAdvanced 3-in-1 Weed and Feed for Southern Lawns
Brand: BioAdvanced. This product combines weed control with lawn feeding, specifically formulated for Southern lawns including St Augustinegrass (Floratam). It offers extended weed prevention lasting up to 6 months and targets listed broadleaf weeds such as dandelion and clover. It’s designed to help maintain a healthy, green lawn while suppressing recurring weed issues through periodic applications aligned with the growing season.
BioAdvanced Season Long Lawn Weed Killer + Preventer for Southern Lawns
Brand: BioAdvanced. This product offers up to 6 months of weed prevention while killing listed broadleaf and grassy weeds. It’s suitable for southern lawns, including St Augustinegrass varieties, and provides a preventive approach that can reduce weed pressure between seasonal applications. When used as part of a broader lawn care plan, it helps maintain a healthy turf and minimizes weed reemergence.
Sunniland St.Augustine Weed & Feed Lawn Fertilizer for St. Augustine Grass
Brand: Generic. This fertilizer-and-weed product is designed for St Augustine grasses and can be split into two applications per year. It emphasizes ease of use with granules and suitability for all St Augustine types. The approach combines feeding with weed suppression to support overall lawn health and vigor, particularly in coastal or warm-season regions where St Augustine thrives.
Buying Guide: Key Purchase Considerations and Comparisons
- Weed types and targets: Different formulas excel at specific weeds (crabgrass, dandelion, clover, Poa annua). Read labels to confirm the weeds listed or suppressed and ensure compatibility with St Augustine or Floratam varieties.
- Lawn type compatibility: Some products are designed for St Augustine and centipede grass, while others are labeled for Southern lawns in general. Verify your grass type and cultivar before application.
- Seasonality and timing: Apply when weeds are actively growing and avoid extreme heat or drought conditions. Some products offer long-term prevention (up to 6 months), which can reduce seasonal reapplications.
- Preventive vs. curative use: Weed-and-feed products can both kill existing weeds and prevent new ones, but effectiveness depends on timing and coverage. Consider integrating post-emergent and preventive options for year-round control.
- Safety and environmental impact: Follow label directions to minimize runoff and protect nearby gardens, water sources, and beneficial organisms. Some formulas are chosen for minimal turf stress during hot months.
- Application method: Sprays and granules require different equipment and handling. Ensure you have appropriate sprayers or spreaders, and calibrate equipment to avoid uneven coverage or over-application.
- Compatibility with fertilizers: If using a weed-and-feed product, coordinate with existing fertilization schedules to prevent nutrient imbalances or burn risks. Consider sequential applications if needed.
- Long-term lawn health: Some products also provide insect control or heat/drought tolerance benefits. Evaluate whether integrated pest management or fertility support aligns with your lawn goals.
- Safety notes: Keep pets and children away during and after treatment as recommended on the label. Store products securely when not in use.