St Augustine grass requires targeted weed control to maintain thick, healthy turf without harming delicate roots. This guide highlights five proven herbicides and related products that are commonly used in American lawns to manage broadleaf and grassy weeds in St Augustine grass and nearby centipede varieties. Each option is evaluated for efficacy, coverage, and compatibility with typical home lawn care routines. Explore the selections below to compare how they fit into seasonal weed management plans and ensure a robust, vibrant lawn.
| Product | Brand | Key Use |
|---|---|---|
| Southern Ag 006130 Atrazine St. Augustine Weed Killer | Southern Ag | Weeds in St. Augustine and Centipede Grasses |
| Southern Ag Atrazine St. Augustine Grass Weed Killer | Southern Ag | Broadleaf weeds; crabgrass suppression |
| Southern Ag Atrazine St. Augustine Grass Weed Killer (with Surfactant) | Southern Ag | Weed control in St. Augustine and Centipede; improved coverage |
| Compare-N-Save Glyphosate Concentrate | Compare-N-Save | General weed and grasses control; non-selective |
| Gordon’s Ornamec 170 Grass Herbicide | GORDON’S | Selective grass weed control around ornamentals |
Southern Ag 006130 Atrazine St. Augustine Weed Killer
Southern Ag 006130 Atrazine St. Augustine Weed Killer is a quart-size solution designed to target weeds within St. Augustine and centipede grasses. It emphasizes weed suppression while remaining suitable for common lawn grasses around ornamental borders. The product’s coverage claims indicate that one quart can treat up to roughly 3,720 square feet, making it practical for mid-size lawns. The formula focuses on controlling both broadleaf weeds and certain grassy invaders to maintain a cleaner lawn profile without excessive resort to repeated applications.
Key features include: effective control of many weeds in St. Augustine and centipede grasses, and a package weight of about 1.021 kilograms. This option is well-suited for homeowners who prefer a high-coverage, single-application approach when the lawn is not under heavy weed pressure. Users should follow label directions for safe application during appropriate growing conditions.
Southern Ag Atrazine St. Augustine Grass Weed Killer
This Atrazine-based weed killer from Southern Ag is designed for St. Augustine grass and is also suitable for centipede lawns. The product provides suppression of crabgrass and helps reduce broadleaf weed populations, contributing to a cleaner turf appearance. It’s presented in a 1-gallon format that aligns with typical lawn maintenance cycles where large weed patches are present, allowing for more economical coverage per application.
Reference features highlight its ability to kill many broadleaf weeds and its versatility across St. Augustine and centipede grasses. The formula supports ongoing weed management, particularly in lawns with mixed weed species. As with all atrazine products, follow label instructions closely to minimize environmental impact and ensure compatibility with your existing lawn care schedule.
Southern Ag Atrazine St. Augustine Grass Weed Killer (with Surfactant)
This variant combines Atrazine weed killer with a nonionic surfactant to enhance coverage and penetration, boosting effectiveness against stubborn weeds in St. Augustine and centipede lawns. The included surfactant helps the active ingredient spread more evenly across leaf surfaces and improves weed suppression performance in varied turf conditions. The product stresses suppression of crabgrass as part of its weed management bundle.
Features emphasize that this weed killer targets common grassy and broadleaf weeds within St. Augustine and centipede lawns, while the surfactant assists with consistent distribution and uptake. This makes it a practical choice for homeowners seeking a streamlined application with built-in enhancements for better results in typical Florida-AND-southern-climates where St. Augustine grass thrives.
Compare-N-Save Glyphosate Concentrate
Compare-N-Save Glyphosate Concentrate provides a non-selective weed control option that is widely used for clearing unwanted weeds and grasses in and around lawns. With a 41% glyphosate concentration, this concentrate can be mixed to create up to 10 gallons of ready-to-use spray, offering flexibility for varying weed densities. It is especially effective for spot treatments and clearing stubborn patches where weeds compete with St Augustine grass for nutrients and water.
The product is rainproof in about two hours, which supports timely re-entry and reapplication planning in outdoor spaces. Homeowners should apply on warm days and avoid applying to desirable ornamentals, and always follow label directions for safe applicator handling and lawn safety. This option is best used as part of an integrated weed-management plan that minimizes impact on the turf when used carefully and correctly.
Gordon’s Ornamec 170 Grass Herbicide
Gordon’s Ornamec 170 Grass Herbicide targets grassy weeds and can be used around ornamental plants, groundcovers, shrubs, trees, landscape beds, and fence lines. It is formulated with fluazifop-P-butyl at 1.70% and is designed for selective control of grassy weeds in mixed landscapes, including proximity to St Augustine and other ornamentals. Application guidance specifies a mix rate of 10 oz per gallon of water, supporting moderate-sized lawn treatment zones and careful integration with ornamental borders.
Ornamec 170 is positioned for homeowners who need targeted control of grassy weeds without broad collateral damage to desirable ornamentals. It emphasizes compatibility with landscape features and surrounding plantings, making it suitable for lawns with borders and decorative plantings. As with any selective herbicide, adherence to label directions is essential to avoid injury to sensitive species and to achieve desired weed suppression outcomes.
Buying Guide: Key Purchase Considerations
- Weed spectrum and lawn type: Choose herbicides that clearly specify St Augustine and/or centipede compatibility. Atrazine-based products are common choices for broadweed suppression in these grasses, while selective grassy weed killers suit borders and ornamental-adjacent areas.
- Herbicide vs. non-selective control: Non-selective options like glyphosate are best for spot treatments and clearing patches, but require caution to avoid turf injury. Selective products target specific weed families and are safer for lawn grasses.
- Coverage and dilution: Review label coverage per unit and dilutions to estimate how many applications you can perform within a season. Surfactants included with some products can improve penetration and performance, particularly in dry or dense weed patches.
- Safety and environmental considerations: Atrazine products require mindful use due to potential environmental concerns. Follow local guidelines and ensure compatibility with garden beds and nearby water sources. Always wear protective gear during application.
- Application timing: Weed control tends to be most effective during active growth periods. Plan applications around early spring or after weed emergence while temperatures are conducive to uptake and minimal turf stress.
- Ornamental surroundings: If your St Augustine lawn borders flower beds or shrubs, consider selective products (Ornamec 170) that minimize drift onto ornamentals and reduce collateral damage.
- Maintenance integration: Use herbicides as part of a broader lawn care plan that includes mowing height adjustments, proper watering, and soil health practices to sustain weed suppression over time.
Additional Perspectives
When selecting an herbicide, homeowners should weigh factors such as the density of weed pressure, the presence of nearby ornamentals, and the specific species targeted. Atrazine-based products are effective for broadweed control in St Augustine lawns but should be used with care to minimize environmental impact and comply with local regulations. Glyphosate options offer rapid, broad-spectrum results for patchwork clearing, yet require precision to protect turf. For lawns with ornamental borders, Ornamec 170 provides a more selective approach to control grassy weeds near plants while reducing the risk to non-target species. A well-rounded lawn care plan combines selective herbicides with cultural practices like proper mowing height, irrigation, and timely fertilization to maintain a resilient St Augustine lawn throughout the growing season.