Best Herbicides and Weed Control for St. Augustine Grass Lawns 2025
Maintaining a healthy St. Augustine grass lawn requires effective weed control to preserve its lush green appearance. Choosing the best herbicide for St. Augustine grass is essential because this turf type is sensitive to many common weed killers. Below is a summary table of top-rated herbicides and weed & feed products specially formulated for St. Augustine grass, efficient in weed elimination while being safe for your lawn.
| Product Name | Brand | Type | Special Features | Treatment Area |
|---|---|---|---|---|
| Southern Ag 006130 Atrazine St. Augustine Weed Killer 32oz | Southern Ag | Liquid Herbicide | Controls weeds in St. Augustine and Centipede grasses | 3,720 sq ft per quart |
| Southern Ag Atrazine St. Augustine Grass Weed Killer, 1 Gallon | Southern Ag | Liquid Herbicide | Kills broadleaf weeds; suppresses crabgrass | Large coverage (gallon) |
| Hi-Yield Atrazine Weed Killer | VPG | Liquid Herbicide | Controls annual bluegrass, chickweed, Poa annua | Designed for St. Augustine and Centipede grass |
| Fertilome St. Augustine Weed & Feed 15-0-4 (12.8 lbs.) | ferti-lome | Weed & Feed Granules | Pre- and post-emergent weed control; fertilizer included | Suitable for multiple southern grasses |
| Scotts Turf Builder Bonus S Southern Weed & Feed2 | Scotts | Weed & Feed Granules | Kills multiple weeds; promotes strong roots | Coverage up to 8,000 sq. ft. |
Southern Ag 006130 Atrazine St. Augustine Weed Killer 32oz Specialty Herbicide
This liquid herbicide from Southern Ag is formulated specifically for St. Augustine and Centipede grasses, treating a practical area of 3,720 sq feet per quart. With a light tan color, it effectively controls weeds typical to these lawn types.
The product’s targeted use ensures minimal harm to your grass while effectively removing unwanted broadleaf weeds and other common lawn invaders. This concentrate is easy to apply and weighs just over one kilogram, making it manageable for homeowners.
Southern Ag Atrazine St. Augustine Grass Weed Killer, 1 Gallon
This one-gallon concentrate covers a large area and is designed to kill many broadleaf weeds while being safe on St. Augustine and Centipede grass. Additionally, it offers suppression of crabgrass, a common nuisance in warm-season lawns.
Its comprehensive weed control properties and volume make it suitable for homeowners with larger lawns seeking to eliminate stubborn weeds while nurturing their turf. Regular use helps maintain a neat and even lawn appearance.
Hi-Yield Atrazine Weed Killer for St. Augustine and Centipede Grass
Hi-Yield Atrazine Weed Killer contains 4.00% atrazine and targets a range of weeds including annual bluegrass, chickweed, and mouse-ear chickweed. Its formulation is safe for use on St. Augustine and Centipede grass varieties.
This selective herbicide is preferred by those wanting effective weed control without compromise to their warm-season lawns. The liquid concentrate allows easy measuring and mixing for practical and precise application.
Fertilome St. Augustine Weed & Feed 15-0-4 (12.8 lbs.)
This dual-purpose granular treatment combines pre-emergent and post-emergent herbicide action with a 15-0-4 fertilizer formula. It targets weeds while nourishing St. Augustine, Centipede, and Zoysia grasses.
Engineered to enhance lawn health by suppressing weed growth and delivering needed nutrients, this product must be used carefully—specifically avoiding Bermuda grasses and northern grass types to prevent damage.
Scotts Turf Builder Bonus S Southern Weed & Feed2
Scotts Turf Builder Bonus S combines weed killing and fertilizer feeding, targeting common southern lawn weeds such as dollarweed, clover, dandelion, and oxalis. It supports strong root development to help St. Augustine grass resist Southern climate stress.
This granular weed & feed product covers up to 8,000 sq. ft. with a single application. It should be applied to a dry lawn and immediately watered in to maximize effectiveness and lawn health.
Buying Guide: Choosing the Best Herbicide for St. Augustine Grass
When selecting an herbicide for St. Augustine grass, consider these important factors to ensure both weed control and lawn safety:
1. Selectivity and Safety for St. Augustine Grass
St. Augustine grass can be sensitive to many herbicides. Use products specifically labeled safe for this grass type to avoid turf damage. Formulations with atrazine are commonly used because they provide effective broadleaf weed control while protecting St. Augustine lawns.
2. Type of Herbicide: Liquid vs. Granular
Liquid herbicides offer precise application and quick absorption, ideal for targeting visible weeds directly. Granular weed & feed products combine fertilizer with weed control for preventive and ongoing lawn health, best for large areas needing nutrition and weed management.
3. Weed Spectrum and Control
Identify the common weeds in your lawn such as dandelions, clover, crabgrass, or chickweed. Choose a herbicide that targets those specific weeds or offers broad-spectrum control. Some products also provide crabgrass suppression which can be beneficial.
4. Coverage Area and Application Frequency
Select a product that matches your lawn size. Concentrates require mixing and are economical for larger yards, while ready-to-use or granular packets may suit smaller areas. Follow label instructions for application intervals to maintain effective control without stressing the grass.
5. Additional Lawn Care Benefits
Some weed killers offer integrated fertilization, improving turf health and resilience. This dual approach can reduce the total number of lawn products needed, encouraging thicker grass that naturally crowds out weeds.
6. Environmental Considerations
Be mindful of potential runoff or impact on nearby plants and water sources. Choose products with responsible formulations and carefully follow safety guidelines to protect pets, children, and pollinators.