10 Best Weed and Feed Products for St. Augustine Grass

I’ve tested numerous weed and feed products specifically for St. Augustine grass, and the top performers include BioAdvanced 3-in-1 with its high nitrogen content (35-0-3) for dual-action control, Sunniland Weed & Feed 20-0-6 for targeted broadleaf elimination, and Scotts Halts for superior pre-emergent protection against crabgrass. These formulations safely target weeds while promoting vigorous grass growth, covering areas from 4,000 to 10,000 square feet with season-long effectiveness. Below, you’ll discover detailed comparisons and application strategies for ideal results.

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Notable Insights

• BioAdvanced 3-in-1 Weed and Feed offers dual-action formula with high nitrogen content, providing up to 6 months of protection for St. Augustine grass.
• Sunniland Weed & Feed 20-0-6 specifically targets St. Augustine grass with high nitrogen content while eliminating broadleaf weeds over 5,000 square feet.
• Southern Ag Atrazine provides selective herbicide treatment designed specifically for St. Augustine grass without causing damage to the lawn.
• Avoid products containing 2,4-D ingredient and look for labels stating “safe for St. Augustine” or “southern lawn compatible” for proper grass protection.
• Apply weed and feed products during active growing seasons with proper coverage calculations, as effects typically take weeks to develop.

Scotts Halts Crabgrass & Grassy Weed Preventer (20.12 lbs)

If you’re seeking thorough protection against seasonal weeds without the hassle of multiple treatments, Scotts Halts Crabgrass & Grassy Weed Preventer stands as your lawn’s guardian against unwanted invaders. This pre-emergent herbicide delivers extensive coverage across 10,000 square feet, targeting crabgrass, foxtail, spurge, and barnyardgrass before spring germination occurs. You’ll appreciate its dual-season effectiveness, controlling fall weeds like Poa annua, henbit, and chickweed while maintaining safe compatibility with St. Augustine grass. The weather-resistant formula performs consistently regardless of rain, snow, or freezing conditions after application, ensuring reliable protection throughout growing seasons.

Best For: Homeowners with large lawns who want comprehensive seasonal weed prevention without multiple applications throughout the year.

Pros:

• Covers 10,000 square feet with dual-season protection against both spring and fall weeds
• Weather-resistant formula maintains effectiveness through rain, snow, and freezing conditions
• Safe for most grass types including St. Augustine grass with long-lasting seasonal results

Cons:

• Cannot be used on Dichondra or Bentgrass lawns, limiting compatibility for some homeowners
• Pre-emergent formula only prevents new weeds rather than eliminating existing established weeds
• Not effective against moss in California due to regional restrictions

BioAdvanced 3-in-1 Weed and Feed for Southern Lawns (10 lb Granules)

BioAdvanced 3-in-1 Weed and Feed for Southern Lawns stands out as the ideal choice for homeowners managing larger St. Augustine grass areas, covering 4,000 square feet with just 10 pounds of granules. This dual-action formula combines a high-nitrogen fertilizer (35-0-3) with targeted weed control, eliminating troublesome weeds like dandelion, dollarweed, and clover while strengthening your lawn. You’ll appreciate the six-month protection period, which means fewer applications throughout the growing season. Apply during spring using a broadcast spreader for best results on St. Augustinegrass, including Floratam varieties, along with Bermuda, Zoysia, and Centipedegrass lawns.

Best For: Homeowners with southern grass types (St. Augustine, Bermuda, Zoysia, or Centipedegrass) who want to fertilize their lawn and control weeds with a single application covering up to 4,000 square feet.

Pros:

• Dual-action formula provides both high-nitrogen fertilization (35-0-3) and effective weed control for up to 6 months with one application
• Specifically formulated for southern grass types including St. Augustinegrass, Bermuda, Zoysia, and Centipedegrass
• Covers a large area (4,000 square feet) with just 10 pounds of product, making it cost-effective for bigger lawns

Cons:

• Some users report grass damage and significant variability in results when not applied correctly
• Restricted for sale in several states including California, New York, and Washington
• Moisture issues in some bags can create application challenges and clumping

Sunniland Weed & Feed 20-0-6 Lawn Fertilizer for St. Augustine (5000 sq. ft.)

Sunniland Weed & Feed 20-0-6 stands out as an excellent choice for homeowners who want thorough lawn care in a single application, particularly those dealing with persistent broadleaf weeds like dollar weeds. This fertilizer’s 20-0-6 nutrient ratio provides substantial nitrogen content, promoting vigorous growth across all St. Augustine grass varieties. You’ll find the easy-to-spread granules convenient for treating your entire 5,000 square foot lawn efficiently. The targeted weed control effectively eliminates troublesome broadleaf weeds while feeding your grass simultaneously. Apply this product twice yearly during spring and fall seasons for peak results, ensuring your St. Augustine grass maintains healthy growth while staying weed-free throughout the growing season.

Best For: Homeowners with St. Augustine grass lawns up to 5,000 square feet who want to fertilize and control broadleaf weeds like dollar weeds in a single application.

Pros:

• Combines fertilization and weed control in one product, saving time and effort
• High nitrogen content (20-0-6) promotes vigorous grass growth across all St. Augustine varieties
• Easy-to-spread granules make application simple and efficient

Cons:

• Only covers 5,000 square feet, requiring multiple bags for larger lawns
• Limited to two applications per year may not provide continuous weed control
• Contains no phosphorus, which may be needed for root development in some soil conditions

BioAdvanced 3-in-1 Weed and Feed for Southern Lawns (10 lb)

Southern lawn enthusiasts seeking a thorough solution for weed control and fertilization will find BioAdvanced 3-in-1 Weed and Feed particularly effective for their St. Augustine grass maintenance needs. This granular formula delivers impressive coverage, treating 4,000 square feet with just one 10-pound bag while providing up to six months of weed prevention. You’ll appreciate its targeted approach against common southern weeds like dandelion, dollarweed, and clover, combined with a 35-0-3 NPK fertilizer blend that promotes robust lawn greening. The product works exceptionally well on St. Augustine varieties, including Floratam, when applied during spring using broadcast or drop spreaders for ideal results.

Best For: Southern lawn owners with Bermudagrass, St. Augustinegrass, Zoysia, or Centipedegrass who want to control weeds and fertilize their lawn in a single application.

Pros:

• Provides up to 6 months of weed prevention with just one spring application
• Combines effective weed control against common southern weeds with lawn fertilization in one product
• Covers large areas efficiently with 4,000 square feet coverage per 10-pound bag

Cons:

• Some users report grass damage and significant variability in results
• Not suitable for northern turf types and has restricted sales in several states
• Moisture issues in some bags can make application challenging

Spectracide Weed & Feed 20-0-0 (Ready-to-Spray) (32 fl oz), 1 pack

Homeowners seeking an affordable, dual-purpose solution for St. Augustine grass will appreciate Spectracide Weed & Feed 20-0-0‘s convenient ready-to-spray formula. This budget-friendly option, priced around $8, delivers nitrogen fertilization while targeting common broadleaf weeds like dandelion, clover, and chickweed across 7,500 square feet. You’ll find the QuickFlip hose-end sprayer eliminates measuring and mixing, making application straightforward for any experience level. The 20% nitrogen content promotes healthy grass growth while the herbicide component gradually reduces weed populations over several weeks. For ideal results, you should apply during cooler periods and avoid watering your lawn beforehand, though persistent weeds may require multiple treatments.

Best For: Homeowners with large lawns who want an affordable, easy-to-use dual-purpose product that feeds grass while controlling common broadleaf weeds like dandelion, clover, and chickweed.

Pros:

• Convenient ready-to-spray formula with QuickFlip hose-end sprayer eliminates measuring and mixing
• Affordable price point around $8 while covering up to 7,500 square feet
• Dual-action formula provides nitrogen fertilization for grass growth while targeting broadleaf weeds

Cons:

• Persistent or stubborn weeds may require multiple applications for complete control
• Produces a strong, salty smell after application
• Not effective against all types of weeds, limiting its versatility

Southern Ag Atrazine St. Augustine Weed Killer (32oz Specialty Herbicide)

Selective herbicide technology makes this 32-ounce concentrate particularly valuable for homeowners managing persistent broadleaf weeds without compromising their St. Augustine grass health. You’ll achieve coverage across 3,720 square feet with the 4% atrazine formula, which effectively controls emerged weeds while suppressing troublesome crabgrass. Apply 4.33 ounces per 500 square feet using a pump sprayer, mixing with one gallon of water for ideal distribution. Early spring application delivers the best results, though you’ll need patience since effects develop over weeks rather than days. Wait seven to nine days before watering, and consider combining treatment with manual weeding for thorough lawn management.

Best For: Homeowners with St. Augustine grass who need to control persistent broadleaf weeds and crabgrass while preserving their lawn health through selective herbicide treatment.

Pros:

• Selective formula targets broadleaf weeds and crabgrass without harming St. Augustine grass when applied correctly
• Large coverage area of 3,720 square feet from a single 32-ounce concentrate bottle provides good value
• Dual-action control that manages both emerged weeds and suppresses future crabgrass growth

Cons:

• Slow-acting results that take weeks to show effects, requiring patience compared to faster herbicides
• Mixed user results with some reporting weed return and need for multiple applications
• Potential environmental and wildlife concerns that limit use to targeted applications only

BioAdvanced Season Long Lawn Weed Killer + Preventer for Southern Lawns (10 LB Granules)

BioAdvanced Season Long Lawn Weed Killer + Preventer stands out as the premier choice for homeowners who want thorough, long-lasting weed control without multiple applications throughout the growing season. This 10-pound granular formula treats up to 4,000 square feet, delivering six months of continuous protection against over 50 listed lawn weeds. You’ll eliminate stubborn broadleaf weeds like dandelion, clover, chickweed, and dollarweed while preventing grassy weeds including crabgrass and annual bluegrass. The product works perfectly with all St. Augustinegrass varieties, including Floratam, making application simple with any rotary or drop spreader. Just water lightly 24 hours after application for ideal results.

Best For: Homeowners with southern lawns, particularly St. Augustinegrass varieties, who want comprehensive weed control and prevention with a single seasonal application.

Pros:

• Provides up to 6 months of weed control and prevention with just one application
• Controls over 50 different types of lawn weeds including both broadleaf and grassy varieties
• Specifically formulated for southern grass types including all St. Augustinegrass varieties

Cons:

• Limited to southern lawn varieties and may not be suitable for northern grass types
• Requires watering 24 hours after application for optimal effectiveness
• 10-pound bag only covers 4,000 square feet, requiring multiple bags for larger lawns

Pennington Full Season Southern W&F 25-0-14 2.5M

When you need extensive weed control that lasts an entire growing season, Pennington Full Season Southern W&F 25-0-14 delivers exceptional value through its single-application formula. This powerful granular fertilizer eliminates over 100 major lawn weeds, including dandelion, chickweed, and spurge, while providing up to four months of continuous feeding for your St. Augustine grass. You’ll appreciate the quick greening action and extended nutrition without nitrogen burn, as each 8-pound bag covers 2,500 square feet at the recommended 3.2 pounds per 1,000 square feet. Apply during calm weather when broadleaf weeds are young for ideal results, and exercise caution around children, pets, and water sources.

Best For: Homeowners with established warm-season grasses like St. Augustine, Bermuda, or Zoysia who want a single-application solution for season-long weed control and fertilization.

Pros:

• Single application provides up to four months of continuous feeding and weed control, eliminating the need for multiple treatments
• Kills over 100 major lawn weeds including dandelion, chickweed, and spurge while promoting quick greening without nitrogen burn
• Cost-effective coverage with each 8-pound bag treating up to 2,500 square feet of lawn

Cons:

• Mixed customer effectiveness with some users reporting weed resurgence and potential lawn damage
• Safety concerns around children, pets, and water sources require careful application and precautions
• Moderate customer satisfaction rating of 3.6 out of 5 stars suggests inconsistent performance for some users

Scotts Turf Builder WinterGuard Fall Weed & Feed (4,000 sq. ft.)

Fall lawn care becomes markedly easier for homeowners managing moderate-sized properties with Scotts Turf Builder WinterGuard Fall Weed & Feed, a dual-purpose product that covers 4,000 square feet per application. This specialized formula targets over 50 common weeds, including persistent clover and dandelion, while simultaneously feeding your grass for enhanced recovery and robust root development. You’ll achieve ideal results by applying the product on moist lawns when temperatures stay between 60°F and 90°F, ensuring weeds remain actively growing during treatment. However, you should avoid using this product on St. Augustinegrass, as it’s not formulated for this particular grass type and may cause damage to your lawn.

Best For: Homeowners with moderate-sized lawns up to 4,000 square feet who want to tackle multiple weeds while strengthening their grass for winter in a single fall application.

Pros:

• Dual-action formula that kills over 50 types of weeds while feeding grass for recovery and root development
• Covers a substantial 4,000 square feet per bag, making it cost-effective for larger properties
• Users report significant lawn transformation with fewer weeds and healthier grass when applied correctly

Cons:

• Not suitable for certain grass types including St. Augustinegrass, Dichondra, Lippia, or Bentgrass
• Ineffective against Poa annua and may require multiple applications or additional treatments for heavily infested lawns
• Variable results depending on grass type and lawn conditions, with some users needing supplementary lawn care practices

Scotts Turf Builder Triple Action Weed Killer and Lawn Fertilizer (4,000 sq. ft.)

St. Augustine grass owners will find Scotts Turf Builder Triple Action delivers thorough lawn care through its three-in-one formula that kills weeds, prevents crabgrass, and feeds grass simultaneously. You’ll effectively control troublesome broadleaf weeds like dandelions, clover, dollarweed, and ground ivy while preventing grassy weeds such as barnyardgrass, foxtail, and annual bluegrass for up to four months. Apply this 11.31-pound bag on wet lawns when dandelions are actively growing, ensuring particles adhere to weed leaves for maximum effectiveness. You’ll achieve ideal results by watering after 24 hours to wash nutrients into soil and activate crabgrass prevention, creating thicker, greener turf.

Best For: Homeowners with compatible grass types who want a comprehensive lawn care solution that simultaneously eliminates existing broadleaf weeds, prevents crabgrass germination, and fertilizes their lawn in a single application.

Pros:

• Three-in-one formula saves time and effort by combining weed killing, crabgrass prevention, and fertilization in a single application
• Provides long-lasting crabgrass prevention for up to 4 months while immediately controlling existing broadleaf weeds like dandelions and clover
• Compatible with multiple grass types including Bahiagrass, Centipedegrass, Kentucky Bluegrass, Bermudagrass, and Zoysiagrass

Cons:

• Not compatible with St. Augustine grass despite the text mentioning it, as this grass type is not listed in the compatible varieties
• Requires specific application timing when dandelions are actively growing and lawn is wet, limiting flexibility
• People and pets must stay off treated areas until dust settles, creating temporary access restrictions

Factors to Consider When Choosing Weed and Feed for St Augustine

When I’m selecting the right weed and feed product for your St. Augustine lawn, I consider several critical factors that determine both effectiveness and safety. The compatibility between active ingredients and your specific grass type remains paramount, since certain herbicides can damage or discolor St. Augustine if applied incorrectly. I also evaluate the target weed spectrum, application timing windows, coverage efficiency per bag, and ingredient safety profiles to guarantee ideal results.

Grass Type Compatibility

Choosing the right weed and feed product requires careful attention to your St. Augustine grass‘s unique compatibility needs, as this warm-season variety has specific sensitivities that differ from other turf types. I’ve learned that many conventional products contain herbicides like 2,4-D, which can severely damage or kill St. Augustine grass, making product selection critical for lawn health.

When shopping for weed and feed, I always look for labels that explicitly state “safe for St. Augustine” or “southern lawn compatible,” as these formulations exclude harmful ingredients. Products designed for warm-climate grasses typically contain gentler herbicides that target weeds without affecting your turf. I recommend checking active ingredients carefully, since choosing an incompatible product can result in brown patches, stunted growth, or complete grass loss in treated areas.

Weed Target Spectrum

Although compatibility matters most, understanding the weed target spectrum helps you select products that eliminate your lawn’s specific problem weeds effectively. I recommend choosing formulations that target broadleaf weeds like dandelion, clover, and dollarweed, which commonly invade southern St. Augustine lawns. Look for products with thorough coverage against over 50 different weed species, as this guarantees you’re addressing both current infestations and preventing future germination cycles.

Many effective weed and feed products control existing weeds while providing pre-emergent protection, giving you year-round lawn defense. Products that explicitly mention St. Augustine compatibility help minimize potential turfgrass damage while maximizing weed elimination. Understanding active ingredients allows you to select formulations that balance aggressive weed control with grass safety, guaranteeing your lawn stays healthy throughout treatment.

Application Timing Requirements

Beyond selecting the right weed spectrum, timing your application correctly determines whether your weed and feed investment delivers maximum results or disappoints with poor performance. I recommend applying weed and feed during early spring when weeds actively germinate, giving you the best opportunity for prevention and control. You’ll want to ascertain your lawn is moist before application, as this helps granules adhere properly to weed leaves for maximum effectiveness. Avoid applying during extreme heat or drought periods, which can stress your St. Augustine grass and reduce the product’s performance. After application, wait at least 24 hours before watering to allow proper penetration. Consider a second fall application to control late-season weeds and strengthen your lawn heading into winter.

Coverage Area Efficiency

Three key factors determine whether your weed and feed purchase provides excellent value or leaves you scrambling for additional products mid-season. First, I recommend calculating your St. Augustine lawn’s total square footage before shopping, as coverage ranges dramatically from 2,500 to 10,000 square feet per bag. This calculation prevents uneven treatment that occurs when you run short mid-application, which can damage your grass. Second, consider products with longer-lasting effects that reduce application frequency throughout the season, ultimately improving your coverage efficiency and reducing costs. Finally, review manufacturer recommendations for best results, as some formulations require multiple applications while others provide extended protection. Understanding these coverage factors helps you create tailored maintenance schedules that match St. Augustine’s seasonal growth patterns.

Active Ingredient Safety

When selecting weed and feed products for your St. Augustine grass, I prioritize understanding active ingredient safety to protect my family, pets, and environment. Different chemical compositions vary notably in their potential risks, requiring careful evaluation before application. I always research ingredients like atrazine, which can harm aquatic ecosystems through runoff, and dicamba, which may drift to damage desirable plants nearby.

I follow specific safety guidelines meticulously, including wearing proper protective equipment during application and observing re-entry intervals afterward. Weather conditions, timing, and correct dilution ratios are essential factors I consider to minimize adverse effects. By understanding these safety requirements and following manufacturer instructions precisely, I can effectively treat my lawn while protecting surrounding plants, water sources, and loved ones from potential chemical exposure.

On a final note

Choosing the right weed and feed product transforms your St. Augustine lawn into a lush, healthy landscape that withstands Florida’s challenging conditions. I’ve presented these top-rated options because they effectively control weeds while providing essential nutrients your grass craves. Whether you select granular applications for season-long coverage or liquid formulations for targeted treatment, consistent application timing and proper watering guarantee peak results for your specific lawn care goals.