Best Weed Control For St Augustine: 10 Options Compared

#1 · Best Overall

1. Southern Ag Atrazine 32 oz

• Weight: 2.1 lb
• Form: Spray

Best for: St. Augustine and centipede lawns.

Why it ranks #1: Explicitly intended for St. Augustine, treats 3,720 square feet per quart, and controls many common grassy and broadleaf weeds, including weeds from seed.

Coverage of about 3,720 square feet per quart makes Southern Ag Atrazine a practical option for treating a sizable St. Augustine or centipede lawn. Its stated activity against emerged weeds and weeds from seed gives it a role in addressing more than visible weeds alone, while the label remains central to application.

This 32-ounce spray herbicide is specified for St. Augustine and centipede lawn grasses, so its listed grass compatibility gives owners of either turf a clear starting point. The product controls many common grassy and broadleaf weeds, and the supplied description also notes suppression of crabgrass. Its stated coverage—one quart for about 3,720 square feet—helps estimate how much lawn a container can treat. Follow label directions, including the listed application rate.

Skip it if you need a hose-connected ready-to-spray applicator; Ortho WeedClear Weed Killer for Lawns offers that application setup.

This suits St. Augustine or centipede owners looking for a spray treatment with stated coverage for roughly 3,720 square feet. Check the label’s application rate and directions, especially when planning coverage for a lawn of a different size.

Listed on Amazon as: Southern Ag 006130 Atrazine St. Augustine Weed Killer 32oz Specialty Herbicide, Light Tan

#2 · Best Weed List

2. Hi-Yield Atrazine 32 oz

• Weight: 2.2 lb
• Form: Liquid

Best for: Atrazine for seasonal lawn use.

Why it ranks #2: Specifically lists St. Augustine and centipedegrass, treats up to 3,720 square feet, and names henbit, dollarweed, chickweed, and clover.

A 32-ounce liquid concentrate with stated coverage up to 3,720 square feet gives Hi-Yield Atrazine buyers a defined lawn-area reference. It is intended for St. Augustine and centipedegrass, controls emerged weeds and weeds from seed, and can be applied during dormant or growing seasons on established turf.

The product lists henbit, dollarweed, chickweed, clover, and sandspur among its targets, helping buyers check whether its weed-control role matches their lawn. Its coverage is up to 3,720 square feet per bottle, while application instructions call for dilution according to the label and lawn dimensions and grass type. That concentrate format requires preparation with a sprayer or watering can. The listing says early spring usually brings the best results and permits use during dormant and growing seasons on established turf.

Skip it if you want to avoid measuring and diluting a concentrate; Ortho WeedClear Weed Killer for Lawns is ready to spray from a hose.

This suits owners of established St. Augustine or centipedegrass who want a measured atrazine concentrate for seasonal use. Factor in dilution and label-specific rates, which vary according to lawn dimensions and grass type.

Listed on Amazon as: Hi-Yield (33430) Atrazine Weed Killer, 32 oz

#3 · Floratam Focus

3. Image Southern Lawns

• Weight: 2 lb
• Form: Liquid

Best for: Floratam and southern lawns.

Why it ranks #3: Designed for southern lawns and explicitly calls out Floratam, a St. Augustine variety; its ready-to-spray format targets broadleaf weeds.

Specific mention of Floratam lawns distinguishes Image Herbicide for Southern Lawns from general lawn weed sprays. Its ready-to-spray format targets tough broadleaf weeds in southern grasses, including St. Augustine, and the listing says visible results can appear in hours while the product kills weeds down to the root.

The liquid lawn weed killer is supplied as a ready-to-spray product, and its instructions say to spray evenly over the lawn, simplifying the application workflow. Its listed turf range includes St. Augustine, Bermuda, and Zoysia, while Floratam is specifically named in the product features. The formula targets tough broadleaf weeds and is described as fast-acting, with visible results in hours. Use it as directed; the supplied information does not state a coverage area.

Skip it if you need an explicit square-foot coverage figure; Southern Ag 006130 states about 3,720 square feet per quart.

This is a fit for southern lawn owners, particularly those with Floratam, seeking ready-to-spray control of tough broadleaf weeds. Because the listing gives no coverage figure, check its label and plan the application accordingly.

Listed on Amazon as: Image Herbicide Weed Killer for Southern Lawns, 32 Oz

#4 · Broad Weed Range

4. Envu Celsius WG Packet

• Weight: 18.14 g
• Form: Powder

Best for: Warm-season post-emergent control.

Why it ranks #4: Celsius is described for warm-season turf including St. Augustine and controls more than 120 annual and perennial broadleaf weeds and grasses.

A compact easy-mix packet is the defining format of this Celsius WG post-emergent herbicide, letting buyers prepare a treatment from a small powder packet. The supplied description names St. Augustine among the warm-season turf types and says the formula controls more than 120 annual and perennial broadleaf weeds and grasses.

Celsius WG is a postemergent, foliar-applied herbicide, so its stated use is treatment of weeds after they have emerged. The description identifies three active ingredients and control of more than 120 annual and perennial broadleaf weeds and grasses in warm-season turf, including St. Augustinegrass. The easy-mix packet and included product label make the preparation format explicit, while the small 0.226-ounce packet is easy to store. Follow the product label for mixing and application directions.

Skip it if you need two seasonal treatments and stated coverage up to 4,000 square feet; Bug And Blade Celsius WG 2-Pack provides those details.

This packet suits warm-season turf owners, including those with St. Augustine, seeking post-emergent control across a broad listed weed range. Its supplied listing does not specify coverage or mixing rate, so use the label to guide preparation.

Listed on Amazon as: Prime Source Celsius WG – 0.226 oz Easy Mix Packet-Post Emerge Weed Control

#5

5. Southern Ag Atrazine Gallon

• Weight: 4.3 oz
• Form: Spray

Best for: One-gallon atrazine supply.

Why it ranks #5: Its listing names St. Augustine grass and reports broadleaf weed control, crabgrass suppression, and activity on emerged weeds and weeds from seed.

The one-gallon container gives St. Augustine and centipede lawn owners a larger-format atrazine option for weed control. Southern Ag lists control of many broadleaf weeds, suppression of crabgrass, and activity on emerged weeds and weeds from seed, supporting a treatment plan that addresses both visible growth and new emergence.

This spray herbicide is identified for St. Augustine grass and is also used on centipede grass, making those turf types its stated fit. Its listed functions include killing many broadleaf weeds, suppressing crabgrass, and controlling emerged weeds and weeds from seed. The one-gallon size provides a larger container format than the brand’s quart listing, though the supplied product details do not state coverage for this gallon. Follow the product label for directions.

Skip it if you need a stated coverage figure to plan a measured treatment; Southern Ag 006130 lists about 3,720 square feet per quart.

Choose this format if Southern Ag atrazine fits your St. Augustine or centipede lawn and you want a one-gallon container. The listed product information does not give coverage, so consult the label when planning the application.

Listed on Amazon as: Southern Ag Atrazine St. Augustine Grass Weed Killer, 1 Gallon

#6 · Two-Season Pack

6. Bug And Blade Celsius WG

• Weight: 12.75 g
• Form: Granule

Best for: Two-treatment warm-season program.

Why it ranks #6: The two-pack is presented for warm-season weed control and claims coverage up to 4,000 square feet, with 120-plus weeds including crabgrass and dollarweed.

Two packets paired with a spring-and-fall treatment plan are the defining features of this Celsius WG bundle. The listing says the treatments cover up to 4,000 square feet and target more than 120 weeds, including crabgrass, dollarweed, and clover, giving warm-season lawn owners a stated seasonal framework.

The product describes one packet for early spring as weeds emerge and a second for late summer or fall, creating a two-application seasonal sequence. It states two gallons per packet and coverage up to 4,000 square feet, useful details for planning mixing and lawn area. The listed weed range includes more than 120 types, with crabgrass, dollarweed, and clover named. Since this is a herbicide application, follow its label directions for preparation and use.

Skip it if you need coverage beyond 4,000 square feet from this listed treatment cycle; The Andersons Barricade covers up to 12,880 square feet.

This bundle suits warm-season lawn owners who want two applications mapped across spring and fall, with named weeds including crabgrass and dollarweed. Its stated coverage is up to 4,000 square feet, so plan around that limit.

Listed on Amazon as: Celsius WG Herbicide 2-Pack with Bug And Blade Weed ID Card

#7

7. Andersons Barricade

• Form: Granule

Best for: Seasonal pre-emergent granules.

Why it ranks #7: Its 40-pound granule covers up to 12,880 square feet and prevents listed weeds, but it is a pre-emergent and will not eliminate existing weeds.

Dispersible granule technology is the defining feature of The Andersons Barricade: after watering, granules disperse into micro-particles that move weed control into the soil. This pre-emergent is intended to prevent weeds rather than eliminate existing ones, making application timing and a clean understanding of its role essential.

The 0.48% prodiamine formula is listed for early spring and fall applications, giving buyers seasonal windows to plan around. Its pre-emergent action targets prevention, including grassy and broadleaf weeds such as crabgrass, poa annua, goosegrass, and henbit; it will not aid in eliminating weeds already present. DG Technology helps granules disperse after contact with water, while coverage of up to 12,880 square feet helps with area planning. Apply only as directed on the label.

Skip it if you need to control emerged weeds now; Southern Ag 006130 also lists control of emerged weeds on St. Augustine.

This is for buyers planning spring or fall prevention across established turf, lawns, landscapes, or ornamental beds. Its pre-emergent role is the boundary: it will not clear existing weeds, and timing matters to performance.

Listed on Amazon as: The Andersons Barricade Professional-Grade Granular Pre-Emergent Weed Control – Covers up to 12,880 sq ft (40 lb)

#8

8. Quali-Pro Prodiamine 65 WDG

• Weight: 5 lb
• Form: Granule

Best for: Prodiamine pre-emergent concentrate.

Why it ranks #8: This prodiamine product is identified for pre-emergent grass and broadleaf weed control, but its listing does not specifically confirm St. Augustine compatibility.

A five-pound supply of prodiamine 65 WDG gives this Quali-Pro product a concentrated granule format for buyers seeking pre-emergent grass and broadleaf weed control. The listing identifies crabgrass control and a generic Barricade comparison, while providing no application coverage or turf-specific directions in the supplied details.

The product is identified as a 65 WDG prodiamine pre-emergent, so its listed role is prevention rather than a stated treatment for weeds already growing. Its features also mention crabgrass control and broadleaf weed control, which can help buyers assess its intended weed-control scope. The five-pound package provides a defined quantity of granules, but the supplied information gives no square-foot coverage, application timing, or St. Augustine compatibility. Check the product label for those operational details before use.

Skip it if you need explicit St. Augustine compatibility and coverage; Southern Ag 006130 lists both the grass type and coverage.

This may suit buyers seeking a prodiamine pre-emergent for grass and broadleaf weed control who can consult its label for application details. The supplied listing does not establish St. Augustine fit or square-foot coverage.

Listed on Amazon as: Prodiamine 65 Wdg 5lbs Pre-emergent Grass Broadleaf Weeds ( Generic Barricade )

#9

9. Ortho WeedClear Ready-To-Spray

• Weight: 8 oz
• Form: Liquid

Best for: Hose-connected lawn spraying.

Why it ranks #9: The ready-to-spray formula kills over 250 common broadleaf weeds, but the supplied product details do not specifically identify St. Augustine as an approved turf.

A ready-to-spray bottle that connects to a garden hose makes Ortho WeedClear a direct choice for buyers who want to apply lawn weed killer without first mixing a concentrate. The product says it kills more than 250 common broadleaf weeds down to the root and produces visible results in hours when used as directed.

The hose-connected sprayer has a simple listed workflow: connect the garden hose, set the nozzle, and switch it on to spray. Ortho says the formula kills more than 250 common broadleaf weeds, including dandelions, clover, chickweed, and dollarweed, without harming the lawn when used as directed. The instructions recommend treating small, actively growing weeds in spring or fall. After drying, the treatment is rainproof in one hour, supporting scheduling around weather.

Skip it if you want an atrazine product specifically listed for St. Augustine; Southern Ag 006130 names that grass and centipede.

This fits lawn owners who value a hose-connected application and broadleaf weed control without mixing concentrate. Its claims are for use as directed, and buyers should check the label’s weed list and application instructions for their lawn.

Listed on Amazon as: Ortho WeedClear Weed Killer for Lawns Ready-To-Spray, 32 fl. oz.

#10

10. Liquid Harvest Mesotrione

• Weight: 8 oz
• Form: Liquid

Best for: Mesotrione broad-spectrum concentrate.

Why it ranks #10: It targets 46 broadleaf species and grasses, but the listed suitable grasses include centipede and not St. Augustine, making compatibility unclear.

Mesotrione’s pre- and post-emergent positioning distinguishes this concentrate for buyers looking at weed control across more than one emergence stage. The listing names 46 broadleaf species and grasses, including crabgrass, clover, chickweed, and dandelion, and notes that full weed death may take two to three weeks.

The 8-ounce liquid concentrate starts absorbing upon application, but the listing says full weed death may take two to three weeks, setting expectations for visible progress. Its targets include 46 broadleaf species and grasses, with crabgrass, clover, chickweed, and dandelion named. Water activates the product; if there is no rainfall within 10 days, the instructions specify applying 0.15 inches of water. St. Augustine is not identified in the supplied turf list, so check the label for compatibility.

Skip it if you need a product explicitly listed for St. Augustine; Southern Ag 006130 names that turf and controls emerged weeds and weeds from seed.

This suits buyers seeking mesotrione concentrate for the listed weeds and who can provide activation water when rainfall does not occur within 10 days. Check the label before using it on St. Augustine.

Listed on Amazon as: Liquid Harvest Mesotrione – 8oz – Mesotrione Concentrate (Compare to Tenacity) – Pre and Post-Emergent Weed Killer for Lawn and Turf Grasses