The problem with most weed-and-feed routines is timing: hit the weeds too late and they’ve already sapped your lawn’s nitrogen, hit them with a straight herbicide and the grass goes pale. The fix is a dual-action granular that delivers a balanced NPK punch right as it strips broadleaf invaders down to the root. What separates a great product from a waste of money comes down to the nitrogen source ratio, the post-emergent active ingredients, and the particle size distribution in the bag.
I’m Mohammad Maruf — the founder and writer behind Gardening Beyond. I’ve spent the past few years studying aggregated owner feedback from thousands of lawn-care buyers across dozens of fertilizer SKUs, comparing NPK profiles, herbicide concentrations, and coverage claims to identify which products actually deliver measurable turf thickening alongside weed mortality.
Whether you’re fighting clover in a cool-season fescue lawn or managing crabgrass in warm-season Bermuda, the right product has to pull double duty without scorching the good grass. This deep-dive guide to the best fertilizer to kill weeds and grow grass breaks down the seven most promising dual-action formulas on the market and helps you pick the one that matches your grass type and weed pressure.
How To Choose The Best Fertilizer To Kill Weeds And Grow Grass
Choosing a weed-and-feed is not a one-size-fits-all decision. Your grass type, the dominant weed species in your lawn, the time of year, and the nitrogen-release profile all determine whether you get a thick green lawn or a patchy, stressed mess. Here’s what to check before you buy.
Match the NPK to your grass type and season
The three numbers on the bag (nitrogen, phosphorus, potassium) tell you the nutritional punch. High-nitrogen ratios like 27-0-5 or 21-0-3 are ideal for cool-season grasses in spring and fall, delivering the N needed for leaf blade density. Warm-season grasses like St. Augustine and Centipede do better with a lower first number like 15-0-4. Avoid products with phosphorus (the middle number) unless a soil test shows deficiency — excess P can run off into waterways and is banned in some regions.
Post-emergent vs. pre-emergent: know the difference
Weed-and-feed products are either post-emergent (they kill existing, visible weeds) or pre-emergent (they prevent weed seeds from germinating). Most dual-action formulas are post-emergent, relying on active ingredients like 2,4-D, dicamba, Mecoprop, or quinclorac to knock down broadleaf weeds. If your main problem is crabgrass or poa annua, you need a product with prodiamine or dithiopyr — but those must go down before the weeds sprout.
Coverage and particle consistency
Bag weight tells you only part of the story. What really matters is the coverage rating in square feet and the particle size uniformity. Fine particles distribute more evenly through a rotary spreader and provide better contact with the weed leaf surface. Coarse particles can leave bare spots or overdosed patches. Brands that specify a uniform granule size or patented technology (like The Andersons’ DG Technology) typically perform more consistently at the labeled spreader setting.
Quick Comparison
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| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| Jonathan Green Green-Up | Post-Emergent Granule | Broadleaf weed control for cool-season lawns | 21-0-3 · 5,000 sq. ft. | Amazon |
| The Andersons Surge 16-0-9 | Post-Emergent Granule | Large lawns with heavy weed pressure | 16-0-9 · 16,000 sq. ft. | Amazon |
| GreenView Fairway Formula | Fertilizer-Only | Thickening lawn without herbicide | 27-0-5 · 10,000 sq. ft. | Amazon |
| The Andersons Barricade 18-0-4 | Pre-Emergent + Fert | Crabgrass prevention in spring | 18-0-4 · 5,000 sq. ft. | Amazon |
| Scott’s Turf Builder Weed & Feed | Post-Emergent Granule | Dandelion and clover knockdown | 2,4-D 1.22% · 5,000 sq. ft. | Amazon |
| Ferti-lome St. Augustine Weed & Feed | Post-Emergent Granule | Warm-season lawns (Centipede, Zoysia, St. Augustine) | 15-0-4 · 5,000 sq. ft. | Amazon |
| Agrisel GrassOut Max | Liquid Post-Emergent | Selective grassy weed control in flower beds | 16 oz concentrate | Amazon |
In‑Depth Reviews
1. Jonathan Green Green-Up Weed & Feed 21-0-3
The Jonathan Green Green-Up Weed & Feed is a mid-range premium performer that nails the balancing act between feeding and weeding. Its 21-0-3 analysis provides a healthy dose of nitrogen for leaf blade development while keeping phosphorus at zero — a smart choice for established lawns where soil phosphorus is already adequate. The fine particle size is a standout feature: smaller granules distribute more uniformly through a drop or rotary spreader, which translates to fewer streaks and more consistent weed knockdown across the entire 5,000 sq. ft. coverage area.
What sets this product apart from the Scott’s alternative is the weed spectrum. Green-Up targets over 250 broadleaf types including tough perennials like poison ivy and thistle, whereas many competitors stop at dandelion and clover. The three-month feeding window is generous for a post-emergent granular; the slow-release nitrogen carriers ensure you see steady greening rather than a surge-and-crash pattern. Be aware that Jonathan Green recommends against using this when overseeding — the herbicide activity can weaken tender new seedlings.
Application timing is mid-spring and early fall for most cool-season turf. A 15 lb bag covers the standard 5,000 sq. ft. residential lawn, which keeps the per-application cost competitive with bagged options that cover less area. The fine granules do demand careful spreader calibration — setting the dial too high can result in overlapping strips and localized herbicide overdose.
What works
- Fine particle size delivers even coverage and better leaf contact
- Controls 250+ weed species including poison ivy and thistle
- Slow-release nitrogen feeds for up to 3 months without surge growth
What doesn’t
- Not compatible with overseeding — herbicide can stunt new grass
- Spreaders need careful calibration to avoid overlapping strips
2. The Andersons Professional Surge Weed and Feed 16-0-9
The Andersons Surge 16-0-9 is a professional-grade post-emergent weed and feed that covers serious ground — literally. The 16-0-9 NPK skews potassium-heavy, which strengthens cell walls and improves drought tolerance, while the four-way herbicide blend eliminates over 250 weeds including dandelions, clover, chickweed, and plantain.
Andersons’ patented DG (dispersible granule) Technology is a genuine engineering advantage: the small, uniform particles dissolve rapidly when watered in, moving the herbicide directly into the soil profile for root-zone contact. This is especially effective in cooler spring and fall temperatures when foliar uptake slows down. The label explicitly warns against use on Floratam St. Augustine, dichondra, and bentgrass — so warm-season Southern lawns need to check compatibility before ordering.
One trade-off with the high coverage is that the nitrogen percentage is lower than some competitors (16% vs. 21% in the Jonathan Green). That means the greening effect is more gradual and less dramatic, but it also reduces the risk of flush growth that demands frequent mowing. For owners of large, established cool-season lawns who prioritize weed mortality over a rapid color change, this is the most efficient option on the list per square foot.
What works
- Huge 16,000 sq. ft. coverage from a single 40 lb bag
- DG Technology ensures rapid dissolution and root-zone herbicide delivery
- Potassium-heavy formula improves turf stress tolerance
What doesn’t
- Not safe for Floratam St. Augustine or bentgrass lawns
- Lower nitrogen content provides slower greening than 21% formulas
3. GreenView Fairway Formula Lawn Fertilizer 27-0-5
The GreenView Fairway Formula is a fertilizer-only product — it contains no herbicide, so it won’t kill existing weeds. It earns its place in this guide because a thick, nitrogen-rich lawn is the most effective long-term weed prevention strategy. The 27-0-5 analysis delivers the highest nitrogen concentration in this review, with 63% of that N in slow-release form. That means you get sustained feeding for up to 12 weeks without the rapid flush that stresses the turf and encourages weed seed germination.
Zero phosphorus is a deliberate environmental choice: GreenView formulates this for areas near waterways or where phosphate runoff is regulated. The 33 lb bag covers a generous 10,000 sq. ft., and the granular texture works well in both broadcast and drop spreaders. The absence of herbicide means you can apply this alongside any post-emergent spray treatment or overseeding project without compatibility concerns.
The trade-off is obvious: if your lawn already has a visible weed population, this bag alone won’t solve it. You’ll need to pair it with a separate post-emergent spray or a pre-emergent granular. But for the budget-conscious homeowner who wants to crowd out weeds by building dense turf, the per-pound nitrogen value here is hard to beat, and the 63% slow-release ratio guarantees you won’t waste nutrients to leaching.
What works
- Highest nitrogen content in the review at 27% with 63% slow-release
- No phosphorus — safe for watershed-sensitive regions
- Works with any standalone herbicide or overseeding plan
What doesn’t
- No herbicide included — existing weeds require separate treatment
- Large 33 lb bag is heavy to carry and store
4. The Andersons Barricade 18-0-4 with Pre-Emergent
The Andersons Barricade 18-0-4 is a pre-emergent weed-and-feed, not a post-emergent killer. Its active ingredient is prodiamine at 0.426%, a proven crabgrass preventer that forms a chemical barrier in the soil to stop weed seeds from germinating. This is the right choice for early spring application when soil temperatures hit 55°F — before crabgrass, goosegrass, and poa annua emerge. Do not expect this product to kill visible weeds; it only prevents new sprouts.
The 18-0-4 fertilizer component delivers moderate nitrogen with 0% phosphorus, which supports steady early-season growth without pushing the lawn too fast. The patented DG Technology works the same way as in the Surge formula: fine, dispersible granules that dissolve quickly on contact with water, ensuring the prodiamine reaches the root zone efficiently. The 18 lb bag covers 5,000 sq. ft., which is standard for this price tier.
The biggest limitation is the narrow application window. Apply too late — after weeds have already emerged — and you’ve wasted the prodiamine. This product also prohibits overseeding for 8 to 12 weeks after application, because the pre-emergent barrier stops grass seed from germinating too. Homeowners who plan to renovate or thicken their lawn with seed in the same season should choose a post-emergent alternative or stagger their applications carefully.
What works
- Effective crabgrass and poa annua prevention with 0.426% prodiamine
- DG Technology delivers fast soil penetration for barrier formation
- Low nitrogen rate prevents flush growth in early spring
What doesn’t
- Will not kill existing weeds — only prevents new germination
- Blocks grass seed germination for 8-12 weeks after application
5. Scott’s Turf Builder Weed and Feed 3
Scott’s Turf Builder Weed and Feed is the most recognizable name in the category, and for good reason: it delivers consistent results on dandelion and clover at a price point that undercuts many specialty brands. The active ingredients are 2,4-D and Mecoprop, a classic broadleaf combination that has decades of field data behind it. Scott’s claims its Weedgrip Technology helps the granules cling to weed leaves (including the ones you can’t see) for better herbicide uptake.
The 5,000 sq. ft. coverage bag keeps the application simple for a standard suburban front lawn. The granular form is easy to broadcast, and the satisfaction guarantee means you can return it if the results don’t meet expectations — a nice safety net for first-time users. The nitrogen content isn’t listed on the spec sheet, but independent tests suggest the feeding component is moderate and fast-release, providing a quick green-up that fades faster than a slow-release formula would.
Where this product falls short versus the Jonathan Green option is the weed spectrum. Scott’s formulation is strongest on dandelion and clover but less effective against tough perennials like wild onion or thistle. If your lawn has a diverse weed population, the broader-spectrum Jonathan Green or The Andersons Surge might be a better fit. The fast-release nitrogen also means you’ll see a growth flush within the first week, requiring a mowing schedule adjustment.
What works
- Proven 2,4-D + Mecoprop blend with strong dandelion knockdown
- Weedgrip Technology improves granule adhesion to weed leaves
- Satisfaction guarantee reduces buyer risk for beginners
What doesn’t
- Narrow weed spectrum — weaker on thistle and wild onion
- Fast-release nitrogen causes a growth flush that needs prompt mowing
6. Ferti-lome St. Augustine Weed & Feed 15-0-4
Ferti-lome’s St. Augustine Weed & Feed is a specialized formulation for warm-season lawns, specifically Centipede, Zoysia, and St. Augustine grass types. The 15-0-4 NPK is deliberately low in nitrogen to avoid the rapid growth that stresses these grasses and invites disease, while the zero phosphorus protects sensitive warm-season root systems. It combines both pre-emergent and post-emergent herbicides to tackle weeds that have already sprouted and prevent future germination.
The 25.6 lb bag covers 5,000 sq. ft., a typical lot size for Southern homes. The dual-mode weed control is a real convenience for warm-season lawn owners who would otherwise need two separate products in early spring. The post-emergent component handles broadleaf weeds like henbit and dandelion, while the pre-emergent part stops crabgrass and other summer annuals before they get a foothold.
The critical limitation is grass-type exclusivity. This product is explicitly unsafe for Bermuda grass and any Northern cool-season grass. If you have a Bermuda lawn or a mixed grass stand, look elsewhere. Also, because the nitrogen release is slower and gentler, the greening effect is more subtle than what you’d get with a high-N product like GreenView. That’s by design for warm-season turf, but some users expect a dramatic color change and may be disappointed.
What works
- Safe for Centipede, Zoysia, and St. Augustine warm-season lawns
- Combines pre-emergent and post-emergent in a single application
- Low nitrogen formula prevents disease-prone flush growth
What doesn’t
- Not safe for Bermuda grass or any cool-season grass type
- Subtle greening may not satisfy users expecting dramatic color change
7. Agrisel GrassOut Max Weed Killer
Agrisel GrassOut Max is not a lawn fertilizer — it is a selective post-emergent herbicide specifically formulated to kill grassy weeds (like crabgrass, foxtail, and wild bermudagrass) without harming broadleaf ornamentals and shrubs. It earns a spot in this review because many “weed-and-feed” products only target broadleaf weeds, leaving grass-on-grass competition unaddressed. The 16 oz concentrate mixes at 1.1 to 2.3 oz per 1,000 sq. ft., making the bottle stretch from 7,000 to 15,000 sq. ft. depending on weed pressure.
The application is liquid, not granular, which gives you pinpoint accuracy in flower beds, tree rings, and along fence lines where a broadcast granule could drift over desirable grass. The three-pack of disposable gloves included is a thoughtful safety addition. Note the label’s explicit warning: this product kills grass, so you must avoid contact with your lawn or any desirable turf species.
The trade-off is that this is a specialty tool, not a general lawn treatment. You’ll need a separate fertilizer program and a separate broadleaf herbicide to maintain the rest of the yard. The liquid concentrate also requires a sprayer (sold separately), adding an upfront cost. But for gardeners who are fighting nutgrass or dallisgrass in their flower beds without wanting to scorch their perennials, Agrisel GrassOut Max is the most targeted solution here.
What works
- Selectively kills grassy weeds in flower beds without harming ornamentals
- Highly concentrated — a 16 oz bottle treats up to 15,000 sq. ft.
- Includes three pairs of protective gloves for safe handling
What doesn’t
- Not a lawn treatment — kills desirable grass on contact
- Requires a separate sprayer and separate fertilizer program
Hardware & Specs Guide
NPK Ratio and Nitrogen Source
The three numbers on the bag represent nitrogen (N), phosphorus (P), and potassium (K). For weed-and-feed products, look for a high first number (18-27) for cool-season grasses or a moderate first number (15-16) for warm-season turf. The nitrogen source matters too: slow-release nitrogen (often listed as water-insoluble nitrogen or WIN) provides steady feeding over 8-12 weeks, while quick-release urea produces an immediate green flush that fades faster. Products like GreenView Fairway Formula explicitly state their slow-release percentage (63% WIN) so you know what you’re getting.
Active Herbicide Ingredients
Post-emergent granulars typically rely on synthetic auxins like 2,4-D, mecoprop (MCPP), dicamba, or quinclorac. These mimic plant hormones and cause uncontrolled growth in broadleaf weeds, leading to death within 1-3 weeks. Pre-emergent formulas use prodiamine, dithiopyr, or pendimethalin to inhibit root development in germinating weed seeds. The concentration (listed as a percentage on the label) determines the kill spectrum: a product with 1.22% 2,4-D like Scott’s is effective on common broadleaf weeds, while a combination of multiple actives (as in The Andersons Surge) covers over 250 species.
FAQ
Can I use a weed-and-feed fertilizer on a newly seeded lawn?
How long does it take to see results from a granular weed-and-feed?
What happens if I apply weed-and-feed when it’s too hot or too dry?
Final Thoughts: The Verdict
For most homeowners with cool-season turf and mixed broadleaf weeds, the best fertilizer to kill weeds and grow grass winner is the Jonathan Green Green-Up Weed & Feed 21-0-3 because it combines a high-nitrogen slow-release feed with the broadest weed spectrum in the granular category. If you manage a large property and want the best per-square-foot value, grab the The Andersons Surge 16-0-9. And for warm-season lawns where grass-type compatibility is non-negotiable, nothing beats the Ferti-lome St. Augustine Weed & Feed 15-0-4.