9 Best Post-Emergent Herbicides [Reviews]

Weeds are the archnemesis of the lawn care enthusiast, so which is the best post-emergent herbicide to arm yourself with to keep your lawn green, healthy, and free of dandelions and other invaders?

Our list of the 9 Best Post-Emergent Herbicides includes a couple of overall champs (selective and non-selective weed killers) and other winners that are best for killing particular weeds, defeating weeds without chemicals, best for fastest results, and best for a weed-and-feed combo. 

We even included a nuclear option, in case you want to get rid of weeds and keep them from returning for a year or more.

First, a quick primer on herbicides:

Herbicides come in two major varieties — pre-emergent and post-emergent. 

• Pre-emergent herbicides act as a preventative measure, keeping weed seeds from germinating (check out our guide to the 8 Best Pre-Emergent Herbicides). 
• Post-emergent herbicides kill weeds that have already sprouted.

Your best defense against weeds in your yard is to apply both pre-emergent and post-emergent herbicides. See our list of the best weed killers overall for a mixture of the different types of herbicides.

There are two main categories of post-emergent herbicides — selective and non-selective. 

• Selective herbicides are spread throughout the lawn, and target weeds while leaving grass alive. 
• Non-selective herbicides kill any plant they come in contact with and are best for hardscaped areas like driveways, edges, and spot treatments.

Now that you know the difference between selective and non-selective herbicides, let’s get to LawnStarter’s picks for the 9 Best Post-Emergent Herbicides, followed by a helpful buyers guide and FAQ.

Top 9 Post-Emergent Herbicides – Reviews

1. Best Selective Post-Emergent Herbicide: Ortho Weed B Gon Plus Crabgrass Control

This selective herbicide is trusted by pros and homeowners across the country. Ortho Weed B Gon kills the most common grassy and broadleaf weeds without harming your grass. This variation on the original Ortho Weed Killer formula takes care of crabgrass, dandelion, thistle, dollarweed, and more.

This post-emergent herbicide is sold ready-to-use, with a spray applicator built into the bottle. It does not require a separate pump sprayer to use. It is also sold as a concentrate to cover more area for the price, with a hose-in sprayer bottle available. The variety of purchase options and wide spectrum of target weeds puts Ortho’s herbicide in our top spot.

Specifications

Active ingredients: Dimethylamine salts, Quinclorac
Packaging: 1-gal ready-to-use. Concentrate in 32 oz and 40 oz 
Selective: Yes
Best for: Crabgrass, dandelion, clover, dollarweed, chickweed, thistle
Required equipment:  None (pump sprayer for concentrated version)
Price range: Moderate

Pros

✓ Covers the full spectrum of common weeds
✓ Lots of purchase options
✓ Works on northern and southern lawns
✓ “Guaranteed” not to kill your lawn grass

Cons

✗ Covers less area than other concentrated herbicides
✗ Reviews indicate it’s less effective on clover

2. Runner-up Selective Herbicide: Southern Ag 2,4-D Amine

Southern Ag’s concentrated dimethylamine salt makes quick work of broadleaf weeds. With each quart covering 20,000 square feet of grass, this post-emergent herbicide will last a while for most residential users.

This 2,4-D post-emergent herbicide, from a brand trusted by pros and homeowners alike, takes the runner-up spot because of its reliability, effectiveness, and value. Unlike our top pick, 2,4-D is not formulated for use on grassy weeds, like dallisgrass, quackgrass, or crabgrass. For this reason, we ranked this post-emergent herbicide No. 2.

Specifications

Active ingredient: Dimethylamine
Packaging: 32 oz concentrate
Selective: Yes
Best for: Dandelion, clover, chickweed, plantain, spurge
Required equipment: Pump sprayer
Price range: Inexpensive

Pros

✓ Top choice of professional lawn care companies
✓ Cost-effective
✓ Works on all turf types

Cons

✗ Doesn’t work on grassy weeds

3. Best Non-Selective Post-Emergent Herbicide: Spectracide Weed and Grass Killer

Non-selective herbicides are less complicated than their selective counterparts. Spray Spectracide on a plant, that plant dies. It’s as simple as that. For getting rid of weeds, grasses, or any unwanted flora in driveways, patios, or sidewalks, Spectracide is the best bang for your buck. It’s sold ready to use — just point and shoot.

Specifications

Active ingredient: Diquat Dibromide
Packaging: 1-gallon jug with sprayer or 1-quart spray bottle
Selective: No
Best for: Killing weeds in landscaped areas, hardscapes, and edges
Required equipment: None
Price range: Inexpensive

Pros

✓ Fast-acting, starts working in 3 hours
✓ Glyphosate-free
✓ Ready-to-use

Cons

✗ Non-selective, kills turfgrass

4. Best Natural Post-Emergent Herbicide: Green Gobbler 20% Vinegar Weed Killer

If the prospect of spreading chemical herbicides turns you off, there’s a simple natural weed killer. Green Gobbler is a vinegar-based non-selective herbicide. Several times stronger than ordinary kitchen vinegar, this stuff is a great spot treatment that’s safe for kids and pets. 

Note: As a non-selective herbicide, you’ll need to follow up with seed to fix the bare patches once the vinegar has run its course.

Pro Tip: Combine this post-emergent herbicide with a corn gluten pre-emergent herbicide for a fully natural weed control system.

Specifications

Active ingredient: Vinegar
Packaging: 1-gallon bottle with sprayer
Selective: No
Best for: Spot-treating weed growth in landscaped areas
Required equipment: None
Price range: Moderate

Pros

✓ Fast-acting: Works in under 24 hours
✓ Organic
✓ Pet- and kid-safe
✓ Ready-to-use

Cons

✗ Non-selective, kills turfgrass

5. Best Herbicide/Fertilizer Combo: Scotts TurfBuilder Weed and Feed

The only granular herbicide on our list, this Scotts TurfBuilder fertilizer/weed killer combo works a little differently than other herbicides. In addition to the 2,4-D herbicide, this granular fertilizer boosts grass growth, crowding out and suffocating the weakened weeds.

Pro Tip: Spread Scotts TurfBuilder on a damp lawn for best effect.

Specifications

Active ingredient: Dimethylamine salts
Packaging: 14- and 40-pound bags
Selective: Yes
Best for: Dandelion, clover, and other broadleaf weeds
Required equipment: Rotary or handheld fertilizer spreader (for best results)
Price range: Moderate

Pros

✓ Fertilizes and boosts growth while killing weeds
✓ Greens up lawn in 48 hours
✓ Easy to spread

Cons

✗ Less effective on crabgrass and other grassy weeds

6. Fastest Results: Gordon’s SpeedZone Lawn Weed Killer

If you need results quickly, Gordon’s SpeedZone may be the right choice for you. This mix of four active ingredients shows results in just hours. SpeedZone works fast enough that you can begin reseeding just two weeks after spraying.

Note: This post-emergent herbicide is formulated for use on cool-season grasses, such as fescue, bluegrass, and ryegrass. It should not be used on warm-season grasses like St. Augustine, bermuda, Zoysia, and bahia. 

Specifications

Active ingredient: Dimethylamine salts, Dicamba acid
Packaging: 20-oz bottle concentrate
Selective: Yes
Best for: Fast results killing broadleaf weeds.
Required equipment: Pump sprayer
Price range: Moderate

Pros

✓ Fastest-acting selective herbicide
✓ Noticeable results
✓ A little goes a long way

Cons

✗ Harmful to bermuda, Zoysia, and other warm-season grasses

7. Best for Crabgrass: Quali-Pro Quinclorac 75 DF

Quinclorac is designed to root out grassy weeds and eliminate them, without harming your lawn. It is the most effective solution to crabgrass on the market, especially when combined with Quali-Pro’s prodiamine pre-emergent.

Specifications

Active ingredient: Quinclorac
Packaging: 1-pound bottle, concentrated granule
Selective: Yes
Best for: Killing crabgrass
Required equipment: Pump sprayer
Price range: Inexpensive

Pros

✓ Best available crabgrass killer
✓ A little goes a long way
✓ Can be mixed with other herbicides

Cons

✗ Not effective on broadleaf weeds

8. Best for Nutsedge: Sedgehammer Plus Turf Herbicide

Nutsedge, which is notoriously difficult to control, can be a real thorn in a lawn enthusiast’s side. Sedgehammer is a specialized product that gets rid of yellow and purple nutsedge, working to the root to prevent further germination.

If you’re patient enough to wait a week or more before seeing results, and you want a tried-and-true nutsedge killer, Sedgehammer is a surefire solution. Because of Sedgehammer’s price per square foot, we recommend using this product as a spot treatment for nutsedge in conjunction with another selective herbicide.

Specifications

Active ingredient: Halosulfuron-methyl
Packaging: 2-pack or 6-pack, 13.5 gram packets
Selective: Yes
Best for: Nutsedge
Required equipment: Pump sprayer
Price range: Expensive

Pros

✓ Effective on nutsedge
✓ Easy to use, just mix and spray

Cons

✗ Slower results
✗ Very targeted — doesn’t work well other weeds
✗ Expensive

9. The Nuclear Option: RM43 Total Vegetation Control

Are you having trouble with weeds in hardscaped areas like gravel, driveways, or sidewalks? If you have plant growth in spots where you want no plants at all, RM43 is a near-permanent solution. This stuff kills everything it touches and renders the soil infertile for up to a year after application.

If you’re tired of weeds growing back where they don’t belong or you want a quick solution to problem areas, RM43 is a perfect choice.

Specifications

Active ingredient: Glyphosate and Imazapyr
Packaging: 1-gallon jug
Selective: No
Best for: Killing all plant life and stopping germination
Required equipment: Liquid sprayer
Price range: Moderate

Pros

✓ Kills weeds. Kills everything.
✓ Prevents new weeds from sprouting for up to a year.

Cons

✗ Non-selective, kills turfgrass and garden plants

Buyers Guide: Post-Emergent Herbicides 

When shopping for a post-emergent herbicide, there are a few main factors that you’ll need to consider — the type of weeds you’re dealing with, the type of grass you have, and your budget.

Grass Type

Warm-season grasses, like bermuda, St. Augustine, and bahia, are similar enough to grassy weeds that certain herbicides will harm them. If you have one of these turf types, make sure your post-emergent is labeled safe to use on southern lawns. Ortho’s Weed B Gon is safe for all grass types. 

A more complicated but safer way to guarantee a selective herbicide won’t harm your lawn is by purchasing the active ingredients separately (Southern Ag 2,4-D and Quali-Pro Quinclorac on this list) and mixing them according to the exact needs of your grass type.

Cool-season grasses, like bluegrass, ryegrass, and fescue, are more robust when it comes to herbicides, but it’s still important to read the label, especially if you’re shopping in an area where both types of lawns are common.

Weed Type

Depending on the type of weed — or the many types of weeds — you’re dealing with in your yard, you’ll need different weapons in your arsenal. 

For example, most post-emergent herbicides are formulated for either broadleaf weeds like dandelion, clover, plantain, and dock, or grassy weeds like crabgrass, dallisgrass, and goosegrass.

If you’re struggling with one or the other, a selective herbicide will treat your lawn with minimal impact on your grass. Use 2,4-D herbicides for broadleaf weeds and Quinclorac herbicides for grassy weeds for best effect. 

If you struggle with one weed in particular, like nutsedge, consider a specially formulated product like Sedgehammer.

If you struggle with a variety of weeds, both grassy and broadleaf, don’t worry. You can purchase a ready-to-use broad-spectrum herbicide or mix your own combination herbicide. Just be sure you follow all the manufacturer’s recommendations and use the full amount of dilution for each ingredient.

Choosing a Non-Selective Herbicide

Non-selective herbicides are more about chemical preference and cost than effectiveness, as they’re all designed to kill any plant matter on contact. 

The three non-selective herbicides on our list are featured for three notable reasons. Spectracide is the least expensive, Green Gobbler is natural and pet-safe, and RM43 keeps weeds from growing back up to a year.

Health and Environmental Tips

Herbicides are safe to use when the manufacturer’s directions are strictly followed. Avoid direct contact between the chemical and your skin. Consult Poison Control if any chemical gets in your eyes or is ingested. 

It should be noted that Glyphosate, the key herbicide in RM43 and several other brand-name herbicides, has been investigated as a carcinogen, or cancer-causing chemical. While results were inconclusive, there’s a degree of controversy surrounding the use of glyphosate that may affect your purchasing decision.

Note: Check your state and local environmental laws before spraying any chemical herbicide. Concerns about chemicals in the groundwater, especially in areas where food is grown, can affect your local statutes governing herbicide and pesticide usage.

FAQ About Post-Emergent Herbicides

When to Call a Lawn Care Pro

The frustration is real for lawn care enthusiasts when weeds spring up and dot your manicured grass. No matter how much work you put into growing a pristine lawn, a few airborne seeds can lead to an outbreak of crabgrass, nutsedge, or poa annua. 

Luckily, there’s a whole market of herbicides and natural solutions available to keep your lawn weed-free. Our list of the 9 Best Post-Emergent Herbicides should help you to keep weeds out of your yard. You may still want to keep a squirt gun of weed killer handy just in case. 

However, if weed control is a losing battle in your yard, or if you simply don’t have time to spread your own herbicide, LawnStarter pros have the knowledge and experience to control the toughest, weediest lawns. Give us a call at 888-822-1766 to learn more about the weeding services we provide in your area.

Main Photo Credit: Mike Mozart / Flickr / (CC BY 2.0)

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