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If you want a thicker, greener St. Augustine lawn with fewer broadleaf weeds, the right weed-and-feed can make a big practical difference. These combined fertilizer-and-herbicide products deliver nutrients and selective weed control in a single application, which matters when turf health and timing both affect recovery after stress. This guide shortlists five top options suited to St. Augustine lawns and evaluates them on nutrient balance, herbicide safety for this grass type, and ease of use. Read on for straightforward guidance about application timing, expected results, and what to watch for in your yard before you apply.
Top Picks at a Glance
| Best Quality Built to a higher standard if you want something more solid | The Andersons Premium Weed and Feed 24-0-16 (18 lb) |  |
| Best Value The sweet spot between price and what you get | Jonathan Green Veri-Green Southern Weed & Feed Fertilizer (5,000 sq ft) |  |
| Best Budget The cheapest option that still gets the job done reliably | Ferti-lome St. Augustine Weed and Feed 15-0-4 |  |
| Highest Rated A top-rated pick with lots of positive feedback | Scotts Turf Builder Bonus S Southern Weed & Feed (2-Pack, 17.24 lb each) |  |
| Most Popular A crowd favorite that many people choose with confidence | Scotts Turf Builder Bonus S Southern Weed & Feed, 17.24 lb (covers 5,000 sq ft) |  |
The Andersons Premium Weed and Feed 24-0-16 (18 lb)
| Item Form | Granule |
|---|---|
| Coverage | 5,000 sq ft |
| Unit Count | 288 Ounce |
| Active Ingredients | Herbicide, Iron, Nitrogen, Sulfur |
The Andersons Premium Weed and Feed 24-0-16 is a granular lawn product designed to kill broadleaf weeds while feeding turf with a mix of quick- and slow-release nitrogen plus iron for deeper greening. You apply it with a rotary or drop spreader to a dry lawn, following the label spreader settings and the two-step application schedule for best control. It targets over 250 broadleaf weeds and lists compatibility with St. Augustine and other common warm- and cool-season grasses, making it useful for seasonal lawn program maintenance. Practical benefits include combined weed control and extended feeding in one pass and improved lawn color from added iron. Important limitations are geographic restrictions and the need to follow the two-application procedure and post-application watering to activate herbicide; it is also not suitable for dichondra or carpet grass. For performance-focused users, correct spreader calibration and adherence to timing will determine results more than the product alone.
Best for: Homeowners who prioritize visible lawn performance and want a combined weed-control plus feeding product for regular seasonal maintenance of St. Augustine and similar grasses.
Less Ideal for: People managing sensitive or restricted lawns such as dichondra or carpet grass or those located in states where this product is not approved.
- Combines herbicide and fertilizer so you kill weeds while feeding grass in one application
- Includes both quick- and slow-release nitrogen for immediate green-up and longer-lasting feeding
- Contains iron for deeper, faster greening of turf
- Covers up to 5,000 sq ft per bag, suitable for medium-sized yards
- Not approved for sale or use in some states which limits availability
- Requires specific spreader settings and a two-step application schedule for full effectiveness
Verdict: Choose this product if you want a single granular treatment that controls broadleaf weeds and delivers both quick and extended feeding for a noticeably greener St. Augustine lawn.
Jonathan Green Veri-Green Southern Weed & Feed Fertilizer (5,000 sq ft)
| Item Form | Granule |
|---|---|
| Coverage | 5000 square foot |
| Unit Count | 184 Ounce |
| N-P-K Ratio | 30-0-3 |
Jonathan Green Veri-Green Southern Weed & Feed combines a 30-0-3 fertilizer with a post-emergent broadleaf weed control designed for warm-season turf. You spread the granules across an established St. Augustine lawn (or other southern grasses) to feed the turf and actively kill more than 40 common weeds such as dollarweed and dandelions. The product is intended for spring or fall application and is most effective when applied to actively growing weeds and watered in or applied to dew-covered grass so granules adhere. The high-nitrogen formula promotes quick greening and denser growth while helping the lawn better withstand heat. Because it is a granular, coverage is easy to measure and the single bag treats up to 5,000 sq ft. Limitations to note are that it is not labeled for cool-season grasses and it is a combined weed-and-feed approach, so you cannot target weeds without also applying fertilizer; follow label directions to avoid overapplication or use on newly seeded areas until safe per instructions.
Best for: Homeowners with established St. Augustine or other southern warm-season lawns who want a single, practical product to both feed turf and reduce broadleaf weeds without complex scheduling.
Less Ideal for: People maintaining cool-season lawns, those seeding new turf where selective fertilization is required, or gardeners who prefer spot-treating weeds rather than treating the entire lawn.
- Formulated specifically for southern warm-season grasses including St. Augustine
- 30-0-3 NPK promotes rapid greening and denser turf
- Controls over 40 common broadleaf weeds
- Granular formula covers up to 5,000 sq ft for straightforward application
- Not suitable for cool-season lawns or where selective weed-only treatment is preferred
Verdict: A convenient, purpose-built weed-and-feed for St. Augustine and other southern warm-season lawns that feeds turf while controlling a wide range of broadleaf weeds across 5,000 sq ft.
Ferti-lome St. Augustine Weed and Feed 15-0-4
| N-P-K | 15-0-4 |
|---|---|
| Intended use | Lawns |
| Target species | Lawn Grass |
This granular 15-0-4 weed-and-feed from Ferti-lome combines a lawn fertilizer with herbicide activity aimed at St. Augustine, Zoysia, and Centipede grasses. It is applied in early spring when lawns are moist and should be watered in after application; those directions help control both pre-emergent and post-emergent weeds while delivering nitrogen for green-up. Typical use is broadcast with a drop or rotary spreader over an established lawn. The product’s straightforward formulation and clear timing make it easy to fit into a seasonal lawn care routine. Practical benefits include a two-in-one treatment that saves an extra step compared with separate fertilizer and weed control products and suitability for warm-season grasses. Important limitations are that it is designed specifically for certain turf types so it is not appropriate for cool-season lawns, and timing and watering are important for effectiveness and to avoid turf injury. Also the listing gives limited detail on active ingredients and coverage rate, so you will need to follow label directions or consult the package for exact application rates.
Best for: Buyers who want a simple, cost-conscious seasonal solution to feed and reduce weeds in established warm-season lawns and prefer a single-step product to simplify spring lawn care.
Less Ideal for: Homeowners with cool-season grasses, newly seeded or sodded lawns, or those who need precise active-ingredient information for sensitive sites should look for alternative products.
- Two-in-one fertilizer and weed control tailored for St. Augustine, Zoysia, and Centipede lawns
- Simple spring application with directions to water in for better control
- Granular form works with standard spreaders for even coverage
- Label in listing lacks specific active ingredient and coverage rate information
- Not formulated for cool-season turf or non-lawn uses
Verdict: A straightforward, budget-friendly weed-and-feed for established St. Augustine, Zoysia, and Centipede lawns that simplifies spring lawn maintenance.
Scotts Turf Builder Bonus S Southern Weed & Feed (2-Pack, 17.24 lb each)
| Item Form | Granule |
|---|---|
| Coverage | 5,000 sq. ft. |
| Number of Packs | 2 |
| Unit Count | 551.68 Ounce |
Scotts Turf Builder Bonus S Southern Weed & Feed combines a weed-killing formula with a slow-release fertilizer designed specifically for southern grass types. It is applied with a broadcast or drop spreader to a dry lawn when grass and weeds are actively growing, then watered in immediately. The formula targets 25-plus southern weed species such as dollarweed, clover, dandelion, oxalis and chickweed while delivering nutrients that help grass fill in as weeds die. This two-pack covers a total of 10,000 sq ft (two 5,000 sq ft bags), which makes it convenient for homeowners with standard-sized yards. Important limitations are its grass-specific label: it is intended only for St. Augustine (including Floratam), Centipede, Zoysia and Carpetgrass and must not be used on Bermudagrass or during dormancy. Proper application requires following spreader settings and watering instructions to avoid uneven treatment. For gardeners in the South who need a dependable, combined control-and-feed product for the right turf types, this product is a practical option.
Best for: Homeowners with St. Augustine, Centipede, Zoysia or Carpetgrass who prioritize a reliable, single-product approach to kill listed southern weeds and feed the lawn.
Less Ideal for: Lawns planted with Bermudagrass, mixed turf that includes non-specified grass types, or gardeners who need year-round treatment for cool-season grasses.
- Combined weed control and slow-release fertilizer reduces the need for separate products
- Targets 25+ common southern lawn weeds including dollarweed and clover
- Formulated specifically for southern turf types to limit grass damage when used as directed
- Two-bag bundle covers 10,000 sq ft, convenient for whole-yard treatment
- Only safe for specific southern grasses and must not be used on Bermudagrass
- Requires precise spreader settings and immediate watering after application for best results
Verdict: A dependable weed-and-feed choice for southern lawns that kills common southern weeds while feeding grass to build thicker turf.
Scotts Turf Builder Bonus S Southern Weed & Feed, 17.24 lb (covers 5,000 sq ft)
| Item Form | Granule |
|---|---|
| Coverage | 5000 square feet |
| Active Ingredients | Atrazine |
| Guaranteed Analysis (N-P-K) | 29-0-10 |
Scotts Turf Builder Bonus S Southern Weed & Feed is a dual-action granular product designed for southern lawns such as St. Augustine, centipede, zoysia, and carpetgrass. You apply it with a broadcast or drop spreader to a dry, actively growing lawn and then water it in immediately; one 17.24 lb bag covers about 5,000 sq ft and the label gives spreader-settings to simplify application. The fertilizer portion (29-0-10 with slowly available nitrogen) feeds the turf to encourage deeper roots and greener color, while the active herbicide atrazine targets more than 25 common southern weeds including dollarweed and clover. Practical benefits include simplified two-in-one treatment and clear timing guidance for late spring or when soil temperatures reach 60 to 85°F. Important limitations: it is not labeled for bermudagrass and must be used only on the specified southern species, and it requires careful handling and watering-in to work as intended. Also, atrazine is a persistent herbicide so follow local regulations and label safety precautions when using near water or sensitive areas.
Best for: Homeowners with St. Augustine, centipede, zoysia, or carpetgrass lawns who want a straightforward, proven two-in-one treatment to reduce broadleaf weeds while feeding turf and who prefer products with broad user feedback.
Less Ideal for: Owners of bermudagrass lawns or gardeners who need an herbicide-free or organic approach should look for alternative products.
- Two-in-one formula that controls listed southern broadleaf weeds while feeding turf.
- Clear application instructions with spreader settings and a coverage figure of 5,000 sq ft.
- Slow-release nitrogen in the fertilizer promotes sustained greening and stronger roots.
- Targets 25+ weeds common to warm, humid southern lawns including dollarweed and clover.
- Not safe for bermudagrass and limited to specific southern grass types.
- Contains atrazine which requires careful handling and attention to local environmental restrictions.
- Requires watering in immediately after application for effectiveness and safety precautions during windy conditions.
Verdict: Choose this if you have a listed southern grass and want a single granular product that reliably kills common southern broadleaf weeds while feeding your lawn.
Choosing the Right St. Augustine Weed and Feed: Key Factors to Consider
Herbicide Type and Selectivity
Different weed-and-feed products use different active herbicide ingredients that vary in which broadleaf weeds they control and how safe they are on St. Augustine grass. Choosing a product with herbicide chemistry labeled for St. Augustine is essential because some herbicides can burn or stunt this grass if applied at the wrong stage or concentration.
Check label lists for the specific weeds prevalent in your yard, such as clover, dollarweed, or spurge. Also note any crop-rotation or contact-postemergent restrictions that could affect overseeding or planting near garden beds.
Nutrient Ratio and Release Type
The fertilizer portion should match your turf's needs. St. Augustine tends to respond well to nitrogen that promotes steady, robust leaf growth but avoid overly high quick-release nitrogen in hot weather, which can lead to scorch or excess thatch. Look for blends with a balance of quick-release and slow-release nitrogen, and appropriate amounts of phosphorus and potassium based on soil test results.
Slow-release forms provide steady feeding and reduce the chance of rapid, vulnerable flushes of growth. If you do not have a recent soil test, choose formulas that are moderate in phosphorus and include slow-release nitrogen to avoid nutrient imbalances.
Timing and Seasonal Suitability
When you apply a weed-and-feed affects both efficacy and turf safety. For St. Augustine, early spring green-up and active weed germination windows are key times, but hot midsummer applications can stress the grass. Several herbicides require cool-season timing or specific growth stages for target weeds to be susceptible.
Read label timing instructions closely and plan applications for calm, mild-weather days to avoid off-target movement. If your lawn experiences summer stress, postpone nonessential treatments until the turf is actively growing and recovered.
Spreader Compatibility and Coverage
Uniform coverage matters because uneven application can leave weed patches or cause localized fertilizer burn. Check that the granule size and recommended spreader settings are compatible with common broadcast or drop spreaders. Labels that provide clear spreader settings for different sizes of lawns reduce guesswork.
Also consider how easy a product is to calibrate and whether it includes guidance for edges and corners. Some blends are dusty or clingy and can complicate even application.
Environmental and Safety Considerations
Weed-and-feed products can impact nearby plants, waterways, and pollinators if misapplied. Choose options with clear runoff guidance, buffer-zone recommendations, and instructions for avoiding application before heavy rain. Some herbicides have restrictions near ornamental beds or vegetable gardens.
Wear appropriate personal protective equipment when applying granular or liquid products, and follow label re-entry and irrigation instructions to limit exposure. If you have a slope or drainage toward water features, prioritize low-runoff or more conservative application methods.
Label Clarity and Instruction
Clear, specific label instructions reduce the chance of misuse. Good labels include spreader settings for common equipment, exact timing windows for St. Augustine, and lists of susceptible and resistant weeds. They also explain whether you need to water after application and how long to wait before allowing pets or people back on the lawn.
Avoid products with vague instructions or missing guidance on mixing, watering, or reapplication intervals, because those gaps increase the risk of turf damage or ineffective weed control.
When to Apply Weed and Feed on St. Augustine Lawns
Apply weed-and-feed when the turf is actively growing but not under heat stress. For many climates, that means early spring as the grass comes out of dormancy and weed seedlings are small and actively growing. Avoid treating during drought or extreme heat.
If you have cool-season weed flushes in late winter or fall, check label timing: some herbicides used in weed-and-feed formulas work best on specific seasonal weeds and may not be effective outside their active window.
- Pick calm, dry days with no rain in the forecast for 24 to 48 hours
- Avoid application immediately before irrigation or heavy rain
- Do a small test area if you are unsure about turf sensitivity
How to Prepare Your Lawn Before Application
Mow to a normal height a few days before applying and remove clippings to improve granule contact with the soil surface. Do not mow immediately before application because clippings can block granules and reduce effectiveness.
Watering history matters. If the lawn is parched, water lightly a couple of days before to reduce plant stress, but avoid heavy irrigation right before applying unless the product label specifies post-application watering is required.
- Clear yard debris and large thatch patches that can prevent contact
- Check soil moisture and turf vigor to avoid applying to stressed grass
Common Mistakes That Harm St. Augustine Grass
Applying during high temperatures or drought can cause scorch and increase the chance of herbicide injury. Some homeowners also overapply, thinking more product yields better results; this often leads to patchy damage.
Using a product not labeled for St. Augustine or ignoring spreader settings are frequent sources of problems. Always follow label guidance for both turf species and spreader calibration.
- Do not apply herbicide when turf is under stress from pests or disease
- Avoid combining treatments unless label explicitly allows tank mixes or sequential applications
Watering and Aftercare Following Application
Follow the product label for whether to water in after application. Some weed-and-feed granules need light irrigation to activate the fertilizer portion, while certain herbicides require no immediate irrigation to remain on leaf surfaces long enough to be absorbed.
Limit foot traffic as recommended on the label and delay mowing for the instructed period to maximize herbicide uptake. Monitor the lawn over the next few weeks: fertilizer response is often visible in leaf color within a week or two, while weed control outcomes may take longer.
- Record the application date and any observations about turf reaction
- If you see signs of turf injury, stop further treatments and follow label first-aid and remediation guidance
Alternatives and Complementary Strategies
Weed-and-feed is one tool among cultural practices that maintain a healthy St. Augustine lawn. Regular mowing at the recommended height, proper irrigation, aeration, and targeted spot treatments for persistent weeds can reduce reliance on broad applications.
Soil testing and targeted fertility programs tailored to your lawn's nutrient needs often yield better long-term results than repeated blanket applications. Consider combining a single season-appropriate weed-and-feed with cultural improvements for best results.
- Use spot herbicides for small, established patches to limit overall chemical use
- Improve soil health through dethatching, aerobic conditions, and organic matter management
How We Chose the Best St. Augustine Weed and Feed
Our selections focus on products that suit the particular needs of St. Augustine turf rather than general-purpose lawn formulas. We prioritized nutrient formulations that support spring and early-summer green-up without encouraging excessive thatch or weak growth. Herbicide profiles were assessed for selectivity and label guidance specific to St. Augustine, favoring chemistries that control common broadleaf weeds while minimizing turf injury risk when used per label. We examined spreader compatibility and application clarity to reduce user error, and we considered how forgiving a product is to timing variations because home gardeners often miss ideal windows. Environmental cautions and runoff risk were part of exclusion criteria, removing blends with high immediate runoff potential or unclear water-use restrictions. Products that required complicated or risky mixing procedures were also excluded. The final list balances fertilizer ratio, weed-control spectrum, application practicality, and safety guidance for St. Augustine lawns.
FAQ
Can I use a generic weed-and-feed on St. Augustine grass?
It depends. Many generic weed-and-feed products list St. Augustine on the label, but others do not. Using a product not labeled for St. Augustine increases the risk of turf injury. Always read the label for both turf species and timing guidance.
How long after applying can I mow or water my lawn?
Label instructions vary. Some products advise waiting 24 to 48 hours before watering or mowing, while others require immediate light irrigation to activate fertilizer. Follow the specific product label for re-entry, mowing, and watering timelines.
Will one application eliminate all broadleaf weeds in my lawn?
One application may control many young or susceptible broadleaf weeds, but tougher or well-established weeds often require follow-up spot treatments or repeated control cycles. Cultural practices like mowing height and overseeding also influence long-term weed pressure.
Is it safe to apply weed-and-feed near flowerbeds or vegetable gardens?
Exercise caution. Granules can drift and herbicide runoff can affect nearby ornamentals or edible plants. Maintain recommended buffer zones and avoid application before heavy rain. If in doubt, protect vulnerable plants with physical barriers during application.
How soon will I see results after application?
Fertilizer effects like deeper green can appear within one to two weeks, but visible weed dieback often takes longer. Some weeds show decline within days, while perennial or woody weeds can require multiple treatments over a season.
Can I overseed St. Augustine after using weed-and-feed?
Many weed-and-feed herbicides restrict overseeding for a defined period because they can inhibit seedling establishment. Check the product label for specific waiting times before seeding or overseeding to avoid poor germination.
Final Verdict
Choosing the right weed-and-feed for St. Augustine turf means balancing selective herbicide chemistry, appropriate nutrient ratios, and correct timing. Prioritize products labeled for St. Augustine, moderate slow-release nitrogen, and clear application instructions to minimize turf stress and environmental risk. Decide based on the weeds you have, your lawn's nutrient needs identified by a soil test, and the seasonal conditions in your yard. When in doubt, favor careful application and integrate cultural practices to get the most reliable, long-term results.
