Finding an effective crabgrass killer for St. Augustine grass is essential for a lush, weed-free lawn. The right product targets crabgrass and other common lawn weeds while protecting your St. Augustine turf. This guide highlights five top options, detailing how each works, where it works best, and what to consider before buying. All selections are suitable for St. Augustine varieties and centipede grasses, focusing on post-emergent and preventive controls to reduce future invasions.
| Product | Brand | Key Feature |
|---|---|---|
| Southern Ag Atrazine St. Augustine Grass Weed Killer, 1 Gallon | Southern Ag | Kills broadleaf weeds; suppression of crabgrass; usable in centipede grass |
| Southern Ag Atrazine St. Augustine Weed Killer 32oz | Southern Ag | Controls weeds in St. Augustine and centipede grasses; treats large area |
| Spectracide Weed Stop For Lawns, 32-Ounce | Spectracide | Targets a wide range of weeds in St. Augustine and centipede lawns; contains atrazine |
| Roundup For Lawns Crabgrass Destroyer2, 64 oz | Roundup | Kills crabgrass to the root; effective against other grassy weeds |
| BASF Drive XLR8 Crabgrass Killer, 64 Ounce | BASF | Post-emergent control with rapid activity; broad-spectrum weed control |
Note: This article compares five products ideal for St. Augustine lawns. Always follow label directions, apply appropriate rates, and observe any seasonal timing recommendations to maximize effectiveness and minimize turf stress.
Southern Ag Atrazine St. Augustine Grass Weed Killer
The Southern Ag Atrazine St. Augustine Grass Weed Killer is designed to be effective on common broadleaf weeds while providing suppression of crabgrass. It is suitable for St. Augustine lawns and can be used in related grass types like centipede. This product is available in a 1-gallon container, making it convenient for larger lawns and multiple-season applications when used per label directions. Apply as directed to target actively growing weeds and avoid applying to stressed or drought-weakened turf.
Southern Ag Atrazine St. Augustine Weed Killer 32oz
Designed for St. Augustine and centipede grasses, this quart-sized formula treats large areas efficiently. It supports weed suppression across broadleaf species and helps reduce weed competition in warm-season lawns. For best results, apply when weeds are actively growing and water-in after application if required by label instructions to improve uptake.
Sunniland St.Augustine Weed & Feed Lawn Fertilizer
This product combines weed control with lawn fertilization, tailored for St. Augustine grasses. It supports weed suppression and turf nutrition in a single treatment, with applications designed for spring and fall timing. Suitable for broad coverage across different St. Augustine varieties, it can be part of an integrated lawn care plan that includes mowing and proper irrigation practices.
Preen Lawn Crabgrass Control – 15 lb.
Preen Lawn Crabgrass Control offers a preventative approach with a large coverage area (15 lb covers about 5,000 sq ft). While primarily a pre-emergent solution, it can be part of a broader strategy for St. Augustine lawns, helping to reduce crabgrass establishment in the growing season. Quick installation and straightforward application support homeowner use for large yard projects.
Spectracide Weed Stop For Lawns
Spectracide Weed Stop For Lawns is a concentrated formula designed for St. Augustine and centipede lawns. It claims to kill a wide range of emerged weeds and those from seeds, with atrazine as part of its active ingredients. The product is designed for ready-to-spray use and provides adjustable coverage for different lawn sizes, making it suitable for targeted weed management as part of a season-long control plan.
Roundup For Lawns Crabgrass Destroyer2
Roundup Crabgrass Destroyer2 is a ready-to-use formulation designed to kill crabgrass at the roots and remove grassy weeds. It is labeled for use on Kentucky bluegrass, fine fescue, perennial ryegrass, and tall fescue, providing a versatile option for mixed-grass lawns. Effective application targets actively growing crabgrass and other grassy invaders, contributing to longer-term weed suppression when paired with proper lawn maintenance.
BASF Drive XLR8 Crabgrass Killer
BASF Drive XLR8 Crabgrass Killer is a post-emergent option featuring quinclorac as the active ingredient. It emphasizes rapid uptake and residual control, offering up to 30 days of protection. The product is designed to work across various weed species in St. Augustine lawns and provides broad-spectrum control for those seeking a robust post-emergent solution with quick visible results.
Buying Guide: Purchase Considerations And Comparisons
- Target weeds: Some formulas focus on crabgrass suppression, while others control broadleaf weeds. Identify whether you primarily need crabgrass eradication or broader weed control for your St. Augustine lawn.
- Post-emergent vs. pre-emergent: If crabgrass is already present, post-emergent products like Roundup Crabgrass Destroyer2 or BASF Drive XLR8 are suitable; pre-emergents (not shown here as primary options) help prevent future germination. Pair strategies for best results.
- Turf compatibility: Ensure the product is labeled for St. Augustine and related grasses (centipede) to avoid turf injury and achieve optimal uptake.
- Application timing: Apply during active weed growth and favorable weather. Avoid extreme heat or drought and follow label instructions for watering, mixing, and safety.
- Coverage and rate: Larger yards benefit from concentrates or multi-quart/gallon sizes. Confirm your lawn area and apply the recommended amounts to avoid overuse and potential turf stress.
- Residual control: Products offering longer residual effects reduce frequent applications but may require careful fit with lawn care routines and irrigation schedules.
- Health and environmental considerations: Look for formulations that minimize non-target impacts and follow local regulations, especially around atrazine-containing products.
- Integrated lawn care: Combine weed control with proper mowing height, irrigation, and seasonal fertilization to maintain a healthy St. Augustine lawn while reducing weed pressure.