Choosing the right fertilizer and weed control for St. Augustine grass can improve color, growth, and weed suppression. This guide highlights five top options and explains how to apply them for best results in American lawns. Each product includes its primary purpose, suitable grass type, and application guidance to help you compare choices quickly.
| Product | Brand | Best For | Approx. Coverage |
|---|---|---|---|
| Southern Ag 006130 Atrazine St. Augustine Weed Killer | Southern Ag | Weed control in St. Augustine and Centipede | Up to 3,720 sq ft per quart |
| LESCO 50 lb. St. Augustine Grass Weed and Feed with Penoxsulam | LESCO | St. Augustine weed and feeding | Coverage depends on rate; 50 lb bag treats large areas |
| Scotts Turf Builder WinterGuard Fall Weed & Feed3 | Scotts | Fall weed control and feeding | Up to 4,000 sq ft |
| Scotts Turf Builder Southern Triple Action | Scotts | Weed control, fire ant prevention, lawn feeding | Up to 4,000 sq ft |
| GreenView Fairway Formula Spring Fertilizer Weed and Feed | Greenview | Spring crabgrass prevention and weed control | Up to 5,000 sq ft |
Note: Always follow label directions for its specific use on St. Augustine grasses. When applying any herbicide or fertilizer, consider local climate, soil type, and lawn conditions to minimize risk to desirable grasses and nearby plants.
Southern Ag Atrazine St. Augustine Weed Killer
Product overview: This weed killer targets broadleaf and grassy weeds within St. Augustine and Centipede grasses. It is labeled for St. Augustine weed control and is sold in a quart container, with coverage described as treating up to 3,720 sq ft per quart. It is designed for light tan packaging and is included for its effectiveness against common lawn weeds in warm-season grasses.
LESCO 50 lb St. Augustine Grass Weed And Feed
Product overview: This professional-grade product is designed specifically for St. Augustine grass. The 50 lb bag includes a formulation described as 13-0-0-17 with sulfur-coated urea, targeted for St. Augustine turf. It emphasizes slow release for up to eight weeks of feeding and is suitable for Floratam varieties. Application timing notes advise applying when the turf is wet and allowing it to dry for best results, with a broad coverage approach based on bag weight.
Scotts Turf Builder WinterGuard Fall Weed & Feed3
Product overview: This product combines weed control with fall fertilization to prepare lawns for spring. It covers up to 4,000 sq ft and targets a variety of listed weeds including common broadleaf species. It is suitable for fall application on cool-season and warm-season grasses when conditions meet label guidance, particularly in southern regions where St. Augustine grass thrives.
Scotts Turf Builder Southern Triple Action
Product overview: A three-in-one formula designed for Southern grass types. It kills listed weeds, prevents and kills fire ants, and feeds the lawn to improve resilience against heat and drought. It targets weeds such as dollarweed, dandelion, clover, oxalis, and plantain, and provides extended protection against pests for up to several months depending on conditions and application rate.
GreenView Fairway Formula Spring Fertilizer Weed and Feed
Product overview: This 18-pound bag provides three key lawn treatments in one application: prevention of crabgrass, weed control, and feeding. It covers up to 5,000 sq ft and claims to kill over 200 broadleaf and grassy weeds, including dandelion and clover, while helping to keep crabgrass at bay for as long as four months. Suitable for early-season use on St. Augustine lawns seeking proactive weed management.
Spectracide Weed & Feed 20-0-0
Product overview: A dual-action formula that both feeds the lawn and kills major broadleaf weeds such as dandelion, chickweed, clover, and plantain. The product features 20% nitrogen to support lawn growth while controlling weeds, providing a balanced option for ongoing maintenance of St. Augustine lawns with visible weed pressure.
Ortho WeedClear Weed Killer For Lawns
Product overview: Ortho WeedClear is a ready-to-spray weed killer designed to control over 250 listed weeds, including dandelion and clover, with results in one application when directions are followed. It is labeled for St. Augustinegrass (not Floratam) and is suitable for spot treatment in lawns with mixed weed pressure. It targets broadleaf weeds while aiming to preserve turf health when used as directed.
Buying Guide
- Know your grass variety: St. Augustinegrass comes in several cultivars (like Floratam and others). Some products are labeled specifically for Floratam or non- Floratam types; choose accordingly to avoid turf injury.
- Seasonality matters: Spring and fall applications address different weed problems. Spring formulations often focus on preventing crabgrass and broadleaf weeds, while fall blends emphasize weed control and lawn prep for winter.
- Weed versus fertilizer balance: Some products prioritize weed control with minimal fertilization, while others provide slow-release nutrients. Decide whether you need primarily weed suppression, nutrient feeding, or a combination.
- Active ingredients and safety: Atrazine-based products can be effective on certain weeds but may have restrictions in some states and on established lawngrass types. Penoxsulam and other compounds have different soil and water runoff considerations; always follow label directions for safety and environmental considerations.
- Application rate and coverage: Bags and bottles specify square footage coverage. For larger lawns, choose products with higher coverage or consider bulk options, ensuring uniform application to avoid burn or under-treatment.
- Safety and compatibility: When treating lawns with multiple products, ensure compatibility to prevent turf damage. If in doubt, perform a small patch test or consult local lawn care guidelines.
- Environmental impact: Consider non-chemical weed control options or selective herbicides where possible to protect beneficial lawn organisms and nearby plants.
- Watering and drying: Many products require the lawn to be moist or slightly wet before application or to dry after application. Follow weather forecasts to optimize effectiveness and minimize runoff.
This guide presents a cross-section of commonly used products for St. Augustine lawns. Always verify product suitability for your specific grass cultivar, local climate, and lawn conditions before purchase and application.