Protecting St. Augustine lawns from persistent weeds requires targeted, granular solutions that feed the grass while controlling unwanted growth. The products below are among the best-rated granular weed killers and weed-and-feed options designed to work with St. Augustine and centipede grasses. Each selection blends weed control with lawn nutrition to help your turf stay thick, green, and resilient through peak growing seasons.
Summary of chosen products
| Product | Type | Coverage | Key Benefit |
|---|---|---|---|
| Southern Ag Atrazine St. Augustine Grass Weed Killer, 1 Gallon | Atrazine Weed Killer | 1 Gallon bottle | Controls common grasses and broadleaf weeds in St. Augustine and centipede lawns; includes crabgrass suppression |
| Southern Ag Atrazine St. Augustine Grass Weed Killer (1 Gallon) with Surfactant | Atrazine Weed Killer with Surfactant | 1 Gallon bottle | Improved coverage and penetration for better weed control in St. Augustine lawns |
| Scotts Turf Builder Bonus S Southern Weed & Feed2, 10,000 sq. ft. | Weed Killer And Lawn Fertilizer | 10,000 sq. ft. | Kills existing weeds and feeds to crowd out future weeds; strengthens roots |
| Scotts Turf Builder Bonus S Southern Weed & Feed2, 5,000 sq. ft. (2-Pack) | Weed Killer And Lawn Fertilizer | 5,000 sq. ft. per bag | Kills existing weeds and thickens grass; helps prevent runoff |
| Scotts Turf Builder Bonus S Southern Weed & FeedF2 Florida Weed Killer and Lawn Fertilizer, 5,000 sq. ft. | Weed Killer And Lawn Fertilizer | 5,000 sq. ft. | Florida-specific weed control with fertilizer for thick, healthy turf |
Below are five in-depth product sections detailing how each option works, what to expect, and who it’s best for. Each entry includes a brief note on application considerations to help you compare at a glance.
Southern Ag Atrazine St. Augustine Grass Weed Killer, 1 Gallon
The Southern Ag Atrazine product is designed to control a broad range of weeds that commonly appear in St. Augustine and centipede lawns. Atrazine targets many grassy and broadleaf species while providing suppression of crabgrass when used as directed. This option is favored for its straightforward one-gallon formulation, enabling coverage over moderate to larger lawns. Users should follow label directions regarding application timing and water-in requirements to maximize effectiveness.
Southern Ag Atrazine St. Augustine Grass Weed Killer (1 Gallon) and Surfactant for Herbicides Non-Ionic
This version pairs Atrazine with a non-ionic surfactant to improve coverage and penetration across leaf surfaces. The surfactant helps the active ingredient reach more of the weed surface, potentially enhancing control in dense or uneven turf. It remains suitable for St. Augustine and centipede lawns, with the same emphasis on crabgrass suppression as part of an integrated weed-management plan.
Scotts Turf Builder Bonus S Southern Weed & Feed2, 10,000 sq. ft.
This Scotts formulation combines weed control with lawn fertilization, designed to kill existing weeds while feeding the lawn to crowd out future growth. It lists several common southern weeds—dollarweed, clover, dandelion, chickweed, oxalis, henbit, purslane, and more—as targets. Apply to a dry lawn when actively growing, and water in after application to activate the fertilizer and herbicide. It’s well-suited for larger homes with lawns around 10,000 square feet.
Scotts Turf Builder Bonus S Southern Weed & Feed2, 5,000 sq. ft. (2-Pack)
The Florida-oriented variant targets a similar spectrum of broadleaf and grassy weeds while offering the benefit of added fertilization to strengthen turf during warm-season growth. This 2-pack is advantageous for homeowners seeking multiple seasonal applications or covering several smaller lawns efficiently. Like other weed-and-feed products, it requires dry lawn conditions and subsequent watering to activate.
Scotts Turf Builder Bonus S Southern Weed & FeedF2 Florida Weed Killer and Lawn Fertilizer, 5,000 sq. ft.
This Florida-specific weed killer and fertilizer is designed to address regionally prevalent weeds while providing steady lawn nourishment. It helps fortify St. Augustine–type grasses against common stressors in warm climates, supporting deeper roots and a robust canopy. Users should follow label guidance on application timing and watering to optimize herbicidal action and nutrient uptake.
Buying Guide: Key Considerations For Granular Weed Killers On St. Augustine Grass
When selecting a granular weed killer or weed-and-feed product for St. Augustine lawns, consider weed spectrum, compatibility with warm-season grasses, and how the product impacts soil and water. The following factors help readers compare options objectively:
- Weed targets: Identify whether you face crabgrass, dollarweed, clover, dandelion, oxalis, or broadleaf weeds. Some formulas emphasize pre-emergent crabgrass suppression, while others focus on broadleaf control alongside fertilization.
- Grass compatibility: Ensure the product is labeled for St. Augustine or centipede lawns and does not contain ingredients unsuitable for warm-season grasses.
- Active ingredients: Atrazine-based options provide broad weed control in many southern lawns, while selective herbicides and pre-emergents may offer different efficacy and environmental considerations. Note label restrictions for certain regions or states.
- Coverage and application rate: Compare square footage coverage per bag or bottle and the recommended dosing. Larger lawns often benefit from higher-unit formulations or multi-pack options.
- Watering-in requirements: Some products require immediate watering after application to activate the fertilizer and herbicide; others rely on rainfall. Plan application timing accordingly.
- Timing and weather: Apply during active weed growth periods and favorable weather. Avoid applying during extreme heat or drought and follow label safety guidelines for pets and children.
- Pet and environmental safety: Consider products with lower non-target impact and follow storage and disposal recommendations to minimize environmental risk.
- Florida-specific or regional formulations: For lawns in hot, humid climates, Florida-specific blends may address local weed pressures and nutrient needs more effectively than general southern formulas.
Overall, the best granular weed killer choice balances immediate weed control with ongoing lawn health. For large properties, a weed-and-feed product can streamline maintenance by combining weed suppression with fertilization. For targeted weed issues, a focused Atrazine-based product or a specialized Florida variant may deliver stronger results in warm-season lawns.