Managing weeds in St. Augustine grass requires effective pre-emergent treatments tailored to the specific needs of this warm-season turf. Below is a summary table featuring the top five pre-emergent products designed to prevent weed growth while supporting St. Augustine grass health.
| Product | Brand | Key Feature |
|---|---|---|
| Southern Ag 006130 Atrazine St. Augustine Weed Killer 32oz | Southern Ag | Controls weeds in St. Augustine and Centipede grasses; 1 quart covers 3,720 sq ft |
| Fertilome (13915) St. Augustine Weed & Feed 15-0-4 (12.8 lbs.) | ferti-lome | Pre-emergent and post-emergent weed control with nutrient-rich fertilizer blend |
| Scotts WeedEx Prevent with Halts, Crabgrass Preventer, 5000 sq. ft. | Scotts | Season-long crabgrass prevention; effective in early spring and fall applications |
| The Andersons Barricade Professional-Grade Granular Pre-Emergent (18 lb) | The Andersons | Professional-grade 0.48% prodiamine; prevents broadleaf and grassy weeds |
| Southern Ag Atrazine St. Augustine Grass Weed Killer, 1 Gallon | Southern Ag | Kills many broadleaf weeds and suppresses crabgrass, suitable for centipede grass |
Southern Ag 006130 Atrazine St. Augustine Weed Killer 32oz
Southern Ag 006130 Atrazine is specifically formulated for St. Augustine and centipede grasses. This specialty herbicide controls broadleaf weeds effectively without harming your turf. One quart treats approximately 3,720 square feet, making it practical for medium-sized lawns. The product is straightforward to apply and absorbs efficiently into the soil to prevent weed seed germination. Its light tan liquid consistency ensures even coverage. This treatment is ideal for homeowners seeking targeted weed control with minimal impact on St. Augustine grass health.
Fertilome St. Augustine Weed & Feed 15-0-4 (12.8 lbs.)
The Fertilome St. Augustine Weed & Feed combines pre-emergent and post-emergent herbicide qualities with a balanced 15-0-4 fertilizer mix. This dual function feeds the lawn while controlling existing and emerging weeds. It is designed especially for Centipede, Zoysia, and St. Augustine grass types. While it effectively manages broadleaf and grassy weeds, it is not suitable for Bermuda or northern grasses. Application is straightforward, making this an excellent choice for homeowners who want both nutrition and weed protection in a single product.
Scotts WeedEx Prevent with Halts, Crabgrass Preventer
Scotts WeedEx Prevent is a trusted pre-emergent herbicide designed to stop crabgrass before it starts. Covering up to 5,000 square feet, this product provides season-long prevention when applied in early spring. It is also effective against winter weeds such as Poa annua, henbit, and chickweed in fall treatments. Scotts WeedEx uses Halts technology to ensure broad-spectrum grassy weed control, making it a versatile choice for maintaining the cleanliness and health of St. Augustine grass lawns during multiple seasons.
The Andersons Barricade Pro-Grade Granular Pre-Emergent
The Andersons Barricade delivers professional-grade pre-emergent weed control with 0.48% prodiamine, effective in early spring and fall applications. It prevents both grassy and broadleaf weeds including crabgrass, goosegrass, and henbit. This granular formula covers up to 5,800 square feet and is designed purely for weed prevention, not for eradicating existing weeds. Suitable for warm-season grasses like St. Augustine, this product is a solid choice for gardeners seeking proactive weed defense with a high-performance formulation.
Southern Ag Atrazine St. Augustine Grass Weed Killer, 1 Gallon
This Southern Ag Atrazine Weed Killer 1-gallon formula targets many broadleaf weeds common in St. Augustine and centipede grass lawns. It also helps suppress crabgrass growth, making it a dual-purpose option for weed management. The larger container size suits bigger yards or repeated applications. Atrazine’s selective action ensures minimal harm to warm-season turfgrass while providing effective weed control. It is ideal for homeowners looking to maintain the lush green appearance of their St. Augustine lawn through multiple growing seasons.
Buying Guide For Pre-Emergent Weed Control in St. Augustine Grass
Choosing the right pre-emergent for St. Augustine grass involves evaluating your lawn’s specific needs and environmental factors. Here are several crucial considerations:
Weed Types Targeted
Different products offer control over various weed species. Some focus on broadleaf weeds, while others prevent grassy weeds such as crabgrass. Identify the predominant weed problems in your lawn to select a targeted formula.
Compatibility With St. Augustine Grass
Not all pre-emergents are safe for St. Augustine grass. Products containing atrazine and prodiamine are generally safe, but always verify to prevent turf damage. Avoid products designed exclusively for northern or cool-season grasses.
Pre-Emergent vs. Weed & Feed
Consider whether you want a standalone pre-emergent or a combined weed control and fertilizer product. Weed & feed options provide nutrition alongside weed prevention but may have restrictions on grass types.
Application Timing & Coverage
Effective pre-emergents require precise timing, typically early spring or fall depending on the weeds targeted. Coverage area per container varies, so choose one that suits your lawn size and allows for proper application rates.
Formulation and Ease of Use
Granular products spread evenly and often require water activation. Liquid herbicides may deliver quicker absorption but can be more complex to apply evenly. Personal preference and equipment availability can influence this choice.
Environmental Factors
Consider climate and local weather patterns. Some products require rainfall or irrigation to activate. Also, be mindful of restrictions in your area related to herbicide usage near water bodies or in sensitive zones.
Existing Weed Presence
Pre-emergents prevent new weeds but typically do not kill established ones. If your lawn already has weeds, a product with post-emergent properties or a separate weed killer might be necessary.
By evaluating these factors, gardeners can select the most effective and compatible pre-emergent weed control product to maintain a healthy, vibrant St. Augustine grass lawn year-round.