Dollarweed challenges St. Augustine lawns, especially in warm southern climates. The right weed killer targets dollarweed and other common broadleaf weeds without harming the grass when used as directed. This article reviews five top products designed to control dollarweed in St. Augustinegrass and explains how they work, when to apply them, and what to expect. Use the following buying guide to compare options and choose the best fit for your lawn care routine.
| Product | Brand | Key Use | Size |
|---|---|---|---|
| Southern Ag Atrazine St. Augustine Weed Killer | Ag | Controls dollarweed and other broadleaf weeds | 32 oz |
| Scotts WeedEx Southern | Scotts Store | Kills dollarweed, clover, and more; for Southern grasses | 4,000 sq ft |
| Scotts Turf Builder Weed and Feed3 | Scotts Store | Weed killer plus lawn fertilizer; broad weed control | Up to 15,000 sq ft |
| Scotts WeedEx Prevent with Halts | Scotts Store | Pre-emergent protection against crabgrass and grassy weeds | 5,000 sq ft |
| Ortho WeedClear Lawn Weed Killer Ready-to-Use1 | Ortho Store | Kills dandelion, dollarweed, and clover; ready to use | 1 gal |
Southern Ag Atrazine St. Augustine Weed Killer
Features include treatment coverage of up to 3,720 sq ft per quart and weed control in St. Augustine and centipede grasses. This product is designed for use in warm-season lawns to target common broadleaf weeds, including dollarweed, with a focus on compatibility with St. Augustinegrass. The package weight is listed at 1.021 kilograms, highlighting a compact, easy-to-store solution.
Scotts WeedEx Southern
WeedEx Southern is formulated to combat dollarweed, clover, dandelion, chickweed, oxalis, and more in Southern lawns. It is designed to perform best when grass and weeds are actively growing and requires immediate watering after application to activate the product. It provides broad-spectrum weed control across multiple common lawn invaders, helping to maintain a thicker, weed-light turf.
Scotts Turf Builder Weed and Feed3
Scotts Turf Builder Weed and Feed3 combines weed control with lawn feeding. This product targets over 50 listed lawn weeds, including dollarweed, dandelion, and clover, while feeding the lawn to promote thicker, healthier turf. Directions specify applying when weeds are actively growing and restricting applications to no more than two times per year. It’s suitable for large areas up to 15,000 sq ft.
Scotts WeedEx Prevent With Halts
This product provides a pre-emergent barrier to stop crabgrass and other grassy weeds before they sprout. It is designed for use in lawns that require ongoing prevention, helping reduce future weed pressures in St. Augustine grass. Application timing is important—follow product directions for timing relative to seasonal growth.
Ortho WeedClear Lawn Weed Killer Ready-to-Use
Ortho WeedClear Ready-to-Use provides fast-action control of common lawn weeds, including dandelion, dollarweed, chickweed, and clover. It is formulated for ready-to-use convenience and is suitable for a variety of lawn grasses, with specific guidance for St. Augustinegrass. Results can appear in hours, making it a popular option for spot treatments and quick relief on smaller patches.
Buying Guide: Key Purchase Considerations
When selecting a dollar weed killer for St. Augustine grass, consider weed spectrum, application method, and compatibility with warm-season grasses. Some products offer pre-emergent protection to reduce new weed growth, while others deliver post-emergent control to target existing patches. Always read the label for active ingredients, safe use on St. Augustinegrass varieties (including Floratam or other cultivars), and required watering or rainfall after application. For larger lawns, blends that combine weed control with fertilization can simplify maintenance, but ensure you do not exceed recommended application rates or frequency.
Effectiveness varies by weed stage. Post-emergent products work best when dollarweed and other weeds are actively growing, while pre-emergents help prevent re-infestation. Consider lawn size to choose a product that covers the area efficiently, and assess whether you want a stand-alone weed killer or a fertilizer-and-weed combination for routine lawn care. For large or highly infested lawns, a staggered approach using a pre-emergent in one season and a post-emergent option the next can balance weed pressure with gradual growth of a healthier turf.
Safety and environmental considerations are important. Follow label directions to minimize impact on non-target plants, pets, and waterways. Store products in a cool, dry place and keep out of reach of children. If you have a lawn with multiple grass types or sensitive areas, you may prefer products labeled specifically for St. Augustinegrass or those that allow targeted spot treatments to reduce overall chemical exposure.
In summary, Costco-wise strategies for dollarweed in St. Augustine lawns often involve a combination of pre-emergent and post-emergent weed control, plus selective fertilization to promote dense turf that crowds out weeds. The listed products offer various approaches, from ready-to-use sprays to granular blends and prevention-focused formulas. Assess your lawn size, weed pressure, and preferred maintenance routine to pick the best option for your yard.