Our readers keep the lights on and my morning glass full of iced black tea. As an Amazon Associate, I earn from qualifying purchases.7 Best Post Emergent Herbicide | No More Weed Guessing

A post-emergent herbicide that falters leaves you staring at a stubborn dandelion or a patch of crabgrass that seems to thrive on your frustration. The problem is rarely the weeds themselves — it’s the spray you chose. The market is flooded with formulas that are either too weak to finish the job or so aggressive they scorch your turf. The right product targets the specific weed without collateral damage to your lawn, your garden beds, or your schedule.

I’m Mohammad Maruf — the founder and writer behind Gardening Beyond. I’ve spent years analyzing herbicide labels, cross-referencing active ingredient concentrations, and tracking thousands of verified owner reports to separate the formulas that deliver lasting control from those that merely wet the leaves.

Whether you are battling broadleaf invaders in cool-season turf or grassy weeds in a warm-season lawn, matching the chemistry to the weed is everything. This guide cuts through the label clutter to help you find the best post emergent herbicide for your specific landscape and level of ambition.

How To Choose The Best Post Emergent Herbicide

The wrong choice can waste an entire growing season. Before you pull the trigger on any bottle or bag, lock in three decisions: the weed spectrum you are fighting, the grass type you are protecting, and the application method that fits your property.

Match the Active Ingredient to the Weed

No single molecule kills everything. 2,4-D and Dicamba dominate broadleaf control on lawns. Quinclorac is the go-to for crabgrass after it emerges. Glyphosate is a non-selective brute force option for driveways and beds. Sulfentrazone and Triclopyr handle tough perennials like wild violet and ground ivy. Read the active ingredient list — not the front-label claims — before deciding.

Selective vs. Non-Selective

A selective herbicide spares your grass while killing the weed. That is the safer route for a lawn you want to keep green. Non-selective formulas like glyphosate kill everything they touch, which is ideal for patios, fence lines, and spot-treating individual stubborn clumps — but catastrophic if drift reaches desirable turf.

Liquid Concentrate vs. Granular Weed-and-Feed

Liquid concentrates give you precise spot control and faster uptake through leaf tissue. Granular products combine fertilizer with post-emergent chemistry, feeding the lawn while suppressing broadleaf weeds — a great one-pass option for large, relatively uniform lawns. The trade-off is slower visual results and reduced effectiveness against established perennial weeds with deep taproots.

Quick Comparison

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Model Category Best For Key Spec Amazon
The Andersons Surge Granular Large lawns, 250+ weeds 16,000 sq. ft. coverage Amazon
Target 6 Plus MSMA Liquid Dallisgrass, tough perennial grass MSMA 48.2% concentrate Amazon
Primesource Quinclorac Liquid Crabgrass & broadleaf control Quinclorac 18.92% Amazon
Albaugh Gly Star Plus Liquid Non-selective total vegetation kill Glyphosate 41% + surfactant Amazon
Select Source Triad TZ Liquid Tough broadleaf suppression 4-way active ingredient blend Amazon
Scotts Weed & Feed5 Granular Dual weed-feed for 4,000 sq. ft. 50+ weeds controlled Amazon
Hi-Yield Grass Killer Liquid Spot-treat grassy weeds near ornamentals Selective post-emergent grass control Amazon

In‑Depth Reviews

Best Overall

1. The Andersons Professional Surge Weed and Feed 16-0-9

Covers 16,000 sq. ft.Targets 250+ weeds

The Andersons Surge combines a four-way herbicide with a 16-0-9 fertilizer analysis, designed to feed the turf while eliminating a massive spectrum of broadleaf weeds. The small-particle formulation delivers more granules per square inch, which translates to better coverage and more uniform uptake across the lawn. The result is a dense, green lawn that naturally crowds out new weeds over the growing season.

Users report rapid knockdown on persistent species like creeping Charlie, dandelion, and chickweed, even when applied in the cooler temperatures of early spring or late fall. The 40-pound bag covers up to 16,000 square feet, making it one of the most cost-efficient options for large properties. The product is not labeled for Floratam St. Augustine, dichondra, or carpetgrass, so check your grass type before spreading.

Several owners noted that proper timing is critical — applying too late in the season or after weeds have already gone to seed reduces effectiveness. For a single-pass weed-and-feed program that covers serious acreage, this is the benchmark in the granular category.

What works

  • Exceptional coverage per bag due to fine granule size
  • Works on over 250 weed types, including creeping Charlie
  • Feeds lawn simultaneously with 16-0-9 analysis

What doesn’t

  • Not safe for all St. Augustine or bentgrass varieties
  • Granular action is slower than liquid spot sprays
  • Large bag requires careful spreader calibration
Pro Grade

2. Target 6 Plus MSMA 48.2% Turf Herbicide

MSMA 48.2%2.5 gal concentrate

Target 6 Plus delivers a concentrated MSMA formulation at 48.2%, making it one of the most potent tools available for selective grassy weed control on golf courses, sod farms, and large residential turf areas. MSMA is the gold standard for suppressing dallisgrass, crabgrass, and certain broadleaf weeds that resist other chemistries.

The recommended mix rate is approximately 2 ounces per gallon of water for general applications, and users emphasize that precise mixing is non-negotiable — overdosing can brown Bermuda grass severely enough to induce premature dormancy. On Japanese zoysia, owners report near-complete elimination of dallisgrass infestations after two applications. The 2.5-gallon jug provides enough concentrate for many seasons of spot treatment.

This product is restricted in some states and requires careful adherence to the label. It is not intended for every homeowner, but for those fighting persistent grass weeds in warm-season turf, MSMA is the closest thing to a silver bullet available.

What works

  • Extremely effective on dallisgrass and tough grassy weeds
  • Highly concentrated; a single jug lasts multiple seasons
  • Fast visible results in warm temperatures

What doesn’t

  • High risk of turf damage if mixed incorrectly
  • Restricted product; not available in all states
  • Strong chemical odor and requires full PPE
Crabgrass Specialist

3. Primesource Quinclorac 1.5L Select

Quinclorac 18.92%64 oz concentrate

Quinclorac is the active ingredient of choice when crabgrass has already emerged and is spreading across your lawn. Primesource packs 18.92% Quinclorac into a 64-ounce jug that, when mixed with a non-ionic surfactant, delivers visible yellowing of crabgrass within 48 to 72 hours. The formula is selective to cool-season and warm-season turf species including Bermuda, fescue, and zoysia, leaving the grass unharmed while the weed rots at the crown.

Users consistently report that a single application eliminates 90 to 98 percent of established crabgrass clumps, though adding methylated seed oil or a surfactant improves adhesion and speeds translocation. The product also controls a broad range of broadleaf weeds including clover, dandelion, and morningglory, making it a versatile addition to any post-emergent arsenal.

The main drawback is cost per ounce — it is one of the more expensive selective herbicides on the market. However, for homeowners who have lost the battle to crabgrass, the investment pays back in one season. Protective gear is recommended, especially when mixing large batches.

What works

  • Fast crabgrass kill visible within 2-3 days
  • Selective to most common turf types
  • Also controls broadleaf weeds like clover and dandelion

What doesn’t

  • Requires separate surfactant for peak performance
  • Premium pricing relative to generic alternatives
  • Must avoid spraying in full sun to prevent leaf burn
Heavy Duty

4. Albaugh Gly Star Plus Glyphosate 41%

Glyphosate 41%2.5 gal jug

Gly Star Plus is a non-selective post-emergent herbicide containing 41% glyphosate with a built-in surfactant system. This means you do not need to buy a separate adjuvant — the surfactants are already blended into the concentrate, saving both time and money. The formula moves systemically from foliage to the root system, delivering complete kill of annual and perennial weeds within 5 to 10 days.

The 2.5-gallon container is intended for commercial and large-scale residential use. Users report that it performs identically to name-brand glyphosate products at a significantly lower per-gallon cost. The built-in surfactant also improves rainfastness and leaf surface adhesion, which is a critical edge when spraying in less-than-ideal conditions.

Because this is a non-selective product, drift onto desirable grass or ornamentals will kill them. Full protective gear — boots, gloves, goggles, and a long-sleeve shirt — is mandatory. Several users stress that proper handling is a matter of safety, not just efficacy.

What works

  • Built-in surfactant saves mixing step and improves performance
  • Professional-grade concentrate at a budget-friendly cost per gallon
  • Systemic action kills weeds down to the root system

What doesn’t

  • Non-selective; kills any green plant it contacts
  • Not labeled for residential use in some jurisdictions
  • Large jug is heavy and requires careful storage
Broadleaf Powerhouse

5. Select Source Triad TZ 4-Way Herbicide

4 active ingredients32 oz liquid

Triad TZ from Select Source packs four active ingredients — 2,4-D, Dicamba, Triclopyr, and Sulfentrazone — into a single quart of liquid concentrate. This broad-spectrum blend is designed for the toughest broadleaf weeds found in residential lawns: wild violet, ground ivy, Virginia buttonweed, and yellow nutsedge suppression. The multi-ingredient approach means that even weeds that have developed resistance to single-action herbicides still get knocked down.

Users report visible wilting within 8 hours on species like spurge and clover, with full death occurring over 1 to 3 weeks depending on temperature and weed maturity. The product is labeled for use on residential lawns, athletic fields, golf courses, and commercial turf, which speaks to its versatility and professional-grade performance.

The smell is notably strong, and the product is toxic if misapplied — overspray on garden plants or exposed skin is a genuine risk. Homeowners should use a dedicated sprayer, wear long sleeves and pants, and shower immediately after application. For anyone dealing with stubborn perennials that cheaper sprays cannot touch, Triad TZ is a legitimate step up.

What works

  • Four active ingredients attack weeds from multiple modes of action
  • Excellent on hard-to-kill species like wild violet and ground ivy
  • Works in cooler spring temperatures, expanding application window

What doesn’t

  • Strong chemical odor during and after application
  • Requires careful spraying to avoid drift onto ornamentals
  • Must use full PPE; product can cause skin irritation
Best Value

6. Scotts Turf Builder Weed and Feed5

Covers 4,000 sq. ft.Granules

Scotts Weed & Feed5 is the household name in granular post-emergent weed control, and for good reason. The 11.32-pound bag covers 4,000 square feet and contains a combination herbicide-fertilizer that targets over 50 common lawn weeds while feeding the grass with nitrogen. The dual action approach thickens the turf over time, which naturally suppresses future weed germination.

The product is designed for use on Bahiagrass, Bermudagrass, Bluegrass, Centipedegrass, Fescue, Ryegrass, and Zoysiagrass — but it explicitly should not be used on St. Augustine (including Floratam), Dichondra, Carpetgrass, or Bentgrass. Application timing is critical: weeds must be actively growing, and daytime temperatures should be between 60°F and 90°F. Applying before rain can reduce efficacy.

Users report that dandelions and clover show visible decline within 3 to 5 days, with full control taking about two weeks. The fertilizer component greens up the lawn noticeably within a week. This is a straightforward, low-mess solution for homeowners who want a single product for both weed control and feeding.

What works

  • Combines weed control and lawn fertilization in one pass
  • Safe for most common cool- and warm-season turf types
  • Easy spreader application with fast visible greening

What doesn’t

  • Not safe for St. Augustine or carpetgrass lawns
  • Granular results are slower than liquid spot treatments
  • Does not control crabgrass or grassy weeds
Spot Treatment

7. Hi-Yield Grass Killer Postemergence Herbicide

Selective for grass8 oz concentrate

Hi-Yield Grass Killer is a selective post-emergent herbicide designed specifically to target grass weeds encroaching on garden beds, around ornamentals, and under shrubs. The 8-ounce concentrate makes up to 8 gallons of spray solution, making it a small-volume tool for precision work. It stops the growth of weed grasses within two days of application, with full death following over the next week.

Users report effective control of tall fescue, Bermuda grass, and Japanese stilt grass when applied directly to the foliage. The selectivity is strong enough that surrounding ornamentals like vinca are left unharmed. However, effectiveness varies by grass species — some cool-season lawn grasses like fescue show resistance, and multiple applications may be needed for established perennial grass weeds.

The bottle is small — 8 ounces — and the packaging does not seem full, which catches some buyers off guard. It is best used as a targeted spot-treatment companion rather than a mass-lawn spray plan. If you are pulling grass out of your flower beds by hand, this is the chemical shortcut you have been looking for.

What works

  • Selective grass killer that spares ornamentals and shrubs
  • Fast action on Bermuda grass and crabgrass within days
  • Concentrated formula makes 8 gallons from one bottle

What doesn’t

  • Ineffective on some cool-season lawn grasses like fescue
  • Small bottle size requires multiple purchases for large areas
  • Results vary significantly by weed grass species

Hardware & Specs Guide

Active Ingredient Concentration

The percentage of the active ingredient in the concentrate dictates how much product you need per gallon of water to achieve a lethal dose. Higher concentrations mean a smaller volume of concentrate per application, which extends the life of a single jug. For example, a 41% glyphosate concentrate requires less product per gallon than an 18% formulation, making the upfront cost-per-ounce less relevant than the cost-per-treated-square-foot.

Selectivity Spectrum

Selective herbicides are formulated to target a specific enzyme pathway or growth mechanism present in weeds but absent in desirable turf. Non-selective herbicides like glyphosate inhibit the EPSPS enzyme, which is universal in green plants. Understanding the weed species you are targeting and the grass type you are protecting is essential before choosing between a broadleaf-specific formula and a total vegetation killer.

Surfactant Requirement

Surfactants reduce the surface tension of water droplets, allowing the herbicide to spread evenly across the waxy leaf cuticle and penetrate the plant tissue. Some concentrates include a built-in surfactant (like Gly Star Plus), while others require a separate non-ionic surfactant or methylated seed oil. Skipping the surfactant on a formula that requires it can cut efficacy by 50 percent or more, especially on hairy-leaved weeds like dollarweed.

Rainfastness Window

Rainfastness refers to the time required after application before rainfall will not wash the herbicide off the leaves. Most post-emergent herbicides need 1 to 6 hours of drying time; glyphosate formulations with built-in surfactants can be rainfast in as little as 1 hour. Granular products require moisture to activate, so rain within 24 hours is usually beneficial for weed-and-feed products, not detrimental.

FAQ

Can I apply a post-emergent herbicide right after mowing?
You should wait at least 2 to 3 days after mowing before applying liquid post-emergent herbicides. Freshly cut grass has open wounds that can absorb the chemical too quickly, leading to turf damage. For granular products, mow 24 hours before application to expose weed foliage, then water the lawn immediately after to activate the granules.
How long should I wait before reseeding after applying a selective herbicide?
Most selective broadleaf herbicides containing 2,4-D or Dicamba require a 2 to 4 week waiting period before reseeding. Quinclorac-based products generally need 3 weeks. Always check the specific label — reseeding too early can kill germinating grass seedlings, effectively wasting both the seed and your labor.
Why is crabgrass still alive a week after spraying Quinclorac?
Quinclorac is temperature-dependent — it performs best when daytime temperatures are consistently above 70°F. If you applied it during a cool spell, translocation within the weed slows significantly. Also, mature crabgrass with multiple tillers may require a second application 10 to 14 days after the first, especially if you did not use a methylated seed oil surfactant.

Final Thoughts: The Verdict

For most homeowners fighting a mixed broadleaf population on a medium-to-large lawn, the best post emergent herbicide winner is The Andersons Professional Surge Weed and Feed because it combines professional-grade chemistry with massive 16,000-square-foot coverage at a cost that undercuts liquid alternatives for large areas. If you need precise crabgrass elimination without harming your Bermuda or fescue, grab the Primesource Quinclorac 1.5L Select. And for non-selective vegetation clearance along fence lines or in garden beds, nothing beats the value and built-in surfactant of Albaugh Gly Star Plus.