St. Augustine grass lawns often struggle with broadleaf weeds and nuisance grasses. The following selection focuses on post-emergent and pre/post options designed to protect St. Augustine, Anthem or similar warm-season turf. Each product below targets common lawn weeds while considering safety for St. Augustine. Read on to compare active ingredients, weed targets, and application notes to choose the right solution for your yard.
| Product | Brand | Key Focus |
|---|---|---|
| Liquid Harvest Mesotrione 8oz | Liquid Harvest | Broadleaf & grassy weeds; pre/post-emergent |
| Sedgehammer Herbicide | SEDGEHAMMER | Nutsedge control |
| Roundup For Lawns₂ Concentrate | Roundup | Crabgrass, broadleaf weeds; lawn-safe |
| Liquid Harvest Mesotrione 32oz | Liquid Harvest | Broadleaf & grassy weeds; pre/post-emergent |
| Liquid Harvest Mesotrione Bundle 8oz | Liquid Harvest | Mesotrione with surfactant; enhanced coverage |
Note: This guide emphasizes products compatible with St. Augustine grass and similar warm-season varieties. Always follow label directions and local regulations when applying herbicides.
Liquid Harvest Mesotrione 8oz
Active ingredient Mesotrione provides post-emergent and pre-emergent control across multiple broadleaf species and grasses. Immediate absorption begins upon application, with full weed death potentially over 2-3 weeks. Water activation is required; if rainfall does not occur within 10 days, apply about 0.15 inches of water. Suitable for St. Augustine grass when used on sod and compatible with other warm-season turf. Avoid certain grasses like bentgrass and poa annua. This product targets common lawn weeds including dandelions, chickweed, clovers, and crabgrass, enabling targeted weed suppression without overly stressing stolons in St. Augustine lawns.
Sedgehammer Herbicide
Designed to control nutsedge species by moving into underground growth points (rhizomes and tubers), Sedgehammer is a targeted option for lawns and landscape areas. It is suitable for established lawns and various non-crop sites, including residential turf and public areas. The product also provides suppression of green kyllinga. This makes it a strong companion in a broad weed management plan for St. Augustine grasses where nutsedge is a frequent issue.
Roundup For Lawns₂ Concentrate
Roundup For Lawns₂ Concentrate is designed for Northern grasses and provides broad-spectrum weed control, including crabgrass and dandelion. It claims rapid action with rainproof performance within a few hours and the ability to provide up to several weeks to months of weed suppression depending on the weed type and conditions. When used as directed on St. Augustine and other warm-season lawns that tolerate the active ingredient, it serves as a versatile option for homeowners facing a mix of broadleaf and grassy weeds.
Liquid Harvest Mesotrione 32oz
This larger 32-ounce bottle expands the same Mesotrione-based solution for broader lawn areas or recurring season needs. It maintains the same action profile: rapid absorption, need for supplemental watering, and effectiveness against 46 broadleaf species and common grasses. It remains suitable for St. Augustine grass on sod, with cautions to avoid propagation in certain grass types. Meshes well with a wider spray program when treating medium to large lawns needing consistent weed suppression.
Liquid Harvest Mesotrione Bundle 8oz
The bundle combines Mesotrione with an 8-ounce supply of surfactant to improve coverage and uptake. Ideal for spots or larger weed patches in St. Augustine lawns, it supports efficient uptake of the herbicide into target weeds. The surface-active agent can help ensure consistent contact with leaf surfaces, potentially speeding up visible results while maintaining safety when used as directed for warm-season turf.
Roundup For Lawns Crabgrass Destroyer2
Designed to tackle crabgrass and similar grassy weeds, this Roundup variant focuses on tough-to-control grasses within lawn settings. It is formulated for use with established turf—including Kentucky bluegrass and tall fescue—and aims to eliminate crabgrass at its source. This product can complement a broader weed control strategy in St. Augustine lawns, especially when crabgrass is a recurring problem aligned with seasonal growth cycles.
Buying Guide: Key Purchase Considerations And Comparisons
Product selection depends on weed type, lawn health, and the tolerance of St. Augustine grass to active ingredients. Consider the following:
- Weed targets: Mesotrione products excel at broadleaf and some grassy weeds, while Sedgehammer focuses on nutsedge. Roundup products provide broad-spectrum control, including crabgrass and many common weeds, but check label specifics for warm-season grasses.
- Application timing: Some products act quickly, while full weed death may take 2-3 weeks. Pre and post-emergent capabilities vary; ensure the product matches your weed cycle and lawn needs.
- Water activation: Mesotrione requires rainfall or irrigation for best results. Plan applications ahead of irrigation or rainfall to optimize efficacy.
- Grass compatibility: Always verify that the product is labeled for St. Augustine or warm-season turf. Avoid treating bentgrass, seashore paspalum, bermudagrass, or other non-target grasses if the label restricts use.
- Safety and environment: Follow PPE recommendations and mixing instructions. Avoid pesticide drift to nearby garden beds or non-target vegetation.
- Surfactants and additives: Bundled products with surfactants can improve coverage on waxy St. Augustine leaves, but ensure compatibility with your overall lawn care program.
- Usage scale: Larger properties may benefit from higher-volume formulations (e.g., 32oz) to cover more area efficiently, while smaller patches can be managed with smaller bottles or bundled options.
- Long-term plan: For persistent weeds like nutsedge, combine selective treatments with cultural practices (mowing height, irrigation, fertilization) to reduce recurrence.
These considerations help compare products beyond price, focusing on weed spectrum, turf safety, and application practicality for St. Augustine lawns.