8 Best Crabgrass Killers for a Clean Backyard

Updated on by Jared Belson | Please note that there may be affiliate links on this page.

If weed and feed fertilizers aren’t yielding the expected results, you might want to consider using one of the best crabgrass killers. They’ll make your lawn look pristine again. You may not be a fan of chemical-based herbicides, but unfortunately, they’re the most efficient.

Below you'll find some of the best crabgrass herbicides that you can use for spot-on and broadcasting treatments. And, there should be something in here for you, regardless of what type of lawn you have or what other weeds are causing a mess on your turf.

8 Best Crabgrass Killers for All Common Grasses

The Drive XLR8 Herbicide can be one of the most potent crabgrass killers when used the right way. For spot-on treatments, the Drive XLR8 works best when mixed with an adjuvant. Use six tablespoons of the XLR8 with three tablespoons of an adjuvant of your choice to get a potent formula that’s also safe to use on your lawn.

This kind of mixture will do wonders, and it can treat up to 2,000sq.ft. But, for broadcasting applications, you may need something three times as concentrated.

Luckily the Drive XLR8 comes in half-gallon containers. So there’s a lot of it to work with. It also has a pretty long shelf life, which means that this is not one of those investments you have to make once or twice a year, maybe not even yearly.

You should know that adding the adjuvant is not mandatory. However, it will boost the post-emergence performance of the XLR8 and thus offer a superior residual control effect.

  • Potent herbicide
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    Can be used for spot-on and broadcasting treatments
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    Easy enough to mix
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    Doesn’t affect the lawn long-term
  • High concentrations may affect grass short-term

This herbicide is one of the cheaper crabgrass weed killers that I strongly recommend. The solution has been designed for spring and late fall application. If you want to take care of your crabgrass invasion, then I recommend treating the problem areas with this product in early spring.

Springtime application helps prevent crabgrass from growing at all. It’s not as efficient used in the summer, when crabgrass may already be fully mature. This formula is more potent against seeds and young root systems.

But, if you can stop crabgrass from growing in the first place, why not take that advantage? The Scotts Halts Preventer can cover an area of 5,000sq.ft. And, it’s one of the best pre-emergence herbicides you can use after successfully dealing with mature crabgrass.

I also like that it’s a resilient formula. Rain or cold weather can’t affect it much.

  • Ready to use out of the box
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    Treats up to 5,000sq.ft.
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    Great residual control
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    Designed for pre-emergence control
  • Unlikely to kill mature crabgrass

This Ortho Weed B Gon concentrate is an effective crabgrass control herbicide, available in most states. The formula is not precisely selective, as it targets well over 200 types of weeds. However, it’s not as harmful to grass, which means that it is safe to use when following the instructions.

I like the fact that the Weed B Gon herbicide doesn’t just kill what’s above the ground. The formula will travel to the roots and kill them, thus stopping weeds from growing back during the season. It’s an excellent choice for post-emergence control, whether you’re doing spot-on or broadcasting treatments.

Another plus in my book is the fact that this formula arrives ready to use. The 32oz bottle canister has enough crabgrass killer for 5,000sq.ft. All you need is a sprayer you can connect to a hose, for broadcasting treatments mostly. Ortho sells those separately.

But, perhaps the most essential feature of this crabgrass killer is its weather resistance. Once sprayed, this mixture takes less than an hour to become waterproof. That means that you can use it virtually anytime.

  • Rainproof after one hour
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    Targets over 200 types of weeds and their roots
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    Great coverage per ounce
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    Won’t affect the lawn
  • Not available in New York and Hawaii

The Prime Quinclorac Select Liquid Crabgrass Killer is one of the more powerful quinclorac-based herbicides. Its formula contains 18.92% active ingredients, and although it seems very similar to the Drive XLR8, it’s much more selective.

This formula has been designed for both residential and non-residential use. You can use it for treating your front lawn, and it’s powerful and safe enough for golf courses too. However, it may be a bit too toxic for use around crop fields.

Although potent, the Quinclorac Select wasn’t designed to be a one-time application herbicide. It’s best to use it as a long-term treatment or at least in two sequential applications. I recommend you use a 1oz application first and then a .9oz application for up to 1,000sq.ft.

As long as you apply the solution between two and three weeks apart, there shouldn’t be any issues. Only some larger types of crabgrass may show some resilience.

  • Designed for sequential treatments
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    Suitable for residential use
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    Waterproof in up to 48 hours
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    Attacks weeds roots
  • Not ideal for time-sensitive landscaping jobs

The Green Light 7642 is a broad-spectrum crabgrass weed killer. It travels to the root system and halts the growth process while also killing already mature weeds. Among the active ingredients, you’ll find the usual quinclorac, dicamba, and dimethylamine salt.

While there’s nothing exceptional about the ingredients themselves, the fact that this formula contains only about 10% active ingredients, means that it’s a bit safer to use. That said, it’s still highly potent even when used for spot-on treatments.

Although it takes a bit longer to kill crabgrass, or any other of the roughly 250 weeds it can target, it still gets the job done in up to three to four days. The first signs of success should show in several hours. You should wait a couple of days before using fertilizer after treating an area with the 7642 Crabgrass Killer Plus.

The Green Light 7642 comes in 32oz containers, and that’s enough to treat an area of up to 6,400sq.ft.

  • Broad-spectrum weed killer
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    Good value for money
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    Great for spot-on treatments
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    Ready to use
  • May require more than one application for large crabgrass strains

This Bayer Advanced formula is ready to spray and is ideal for the broadcasting treatments. It effectively kills over 200 weeds, including crabgrass. It should have minimal impact on lawns as long as you spray it according to the instructions on the label.

Bayer offers no clear garden hose PSI recommendations, but you should know that the 32oz premixed formula should be enough for 5,000sq.ft.

To get the best results, you’ll want to use the All in One Weed & Crabgrass Killer when the temperature is under 90 degrees Fahrenheit. Also, note that this is a post-emergence herbicide. So make sure to spray it when the crabgrass is actively growing and not before, as it will have a little effect then.

I like that there are no special requirements to spread the herbicide over lawns. The bottle sprayer should connect to your standard garden hose, and can handle some high-pressure settings too.

The adjustable sprayer nozzle also helps maintain an even dispersal pattern and avoid any herbicide build-ups over the clean lawn.

  • Comes in a sprayer bottle
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    Ready to use
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    Great coverage
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    Becomes waterproof in under one hour
  • Slightly expensive given the slow action formula

You can get this Spectracide crabgrass killer in 24oz, 32oz, one-gallon containers, as well as in packs of four or six. It’s the ideal choice if you have a vast property, or if you’re planning on starting your own small landscaping business.

The formula is professional-grade, though perhaps not as harmful to lawns and ornamental plants as most other herbicides. There’s no need to do any mixing yourself, which makes this the right choice for spot treatments.

The formula acts by traveling down to the root system and systematically destroying it. Results should show within eight hours of application. However, unlike other similar herbicides, this one takes up to three hours to become waterproof.

You need to be more mindful of the weather conditions when you use it, and also remember to turn off any sprinklers for a while.

  • Starts killing the roots in under eight hours
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    Decent waterproofing
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    Ready to use
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    Major broadleaf and crabgrass control herbicide
  • Takes up to three hours to become waterproof

There are a few variations when it comes to the Roundup Lawns1 herbicide. The differences, however, boil down to the container the herbicide comes in and the dispersal method. I recommend the Comfort Wand version as it’s ready to use, and you can use it for accurate, spot-on treatments.

The narrow dispersal pattern can ensure that you will be able to treat your lawn close to the ornamental plant beds without spraying where you shouldn’t.

Although effective against a wide range of weeds, there are just four types against which the Roundup 4385010 truly shines: crabgrass, dandelion, clover, and yellow nutsedge.

The effect is almost immediate, with the results starting to show in a few hours. It also takes up to three hours before the formula becomes rainproof. So, it doesn’t dry up too fast, but fast enough if you’re using it during springtime or late fall.

I should also mention that you might not want to use this particular formula for very tough or large crabgrass. Those hard-to-kill varieties may require more than one treatment over an extended period or a more potent formula from the start.

  • Broad-spectrum crabgrass killer
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    Comes with the comfort wand applicator
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    Safe for many northern and southern kinds of grass
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    Kills roots in a matter of hours
  • May not be as effective against hard-to-kill species

Why Is Crabgrass Dangerous for Lawns?

Most people have a hard time understanding why is crabgrass considered a weed. After all, it’s a grass and not a weed so it couldn’t be that bad. Well, not exactly.

First of all, crabgrass, as far as grasses are concerned, is not desirable on a lawn since it’s an annual grass. That makes it difficult to maintain as opposed to perennial grasses, which only need to be seeded once every few decades.

Crabgrass can overpower your lawn, especially during warmer periods like late spring and summertime. For lack of a better term, it’s also an ugly type of grass due to its messy growth pattern and general unevenness.

Although it’s unlikely that crabgrass will grow in more than a few spots, you shouldn’t leave it uncontrolled for a long time. Otherwise, it will spread, and eventually, your lawn will be riddled with brown patches and new crabgrass spots. It may even be able to suffocate certain types of sensitive lawns if left unchecked.

Is Using Adjuvants Good or Bad?

It depends on what type of herbicide you’re using. Not all herbicides require adjuvants. If present, however, adjuvants are substances that are either added directly to spray tanks by the user or to the formula by manufacturers.

These substances can improve either the application or the performance of a herbicide. As such, there are two classes of adjuvants called activators and special-purpose adjuvants.

Both can be beneficial in certain conditions. For example, some crabgrass killers might need an activator adjuvant to make the formulation more efficient as a post-emergence herbicide. Or, it could slightly alter the crabgrass killer’s composition so that the crabgrass will absorb it quicker and transport the solution down to the roots.

It’s only wrong to add adjuvants if the formulas already contain them or if you’re adding the wrong type. But, manufacturers usually point out all the necessary information regarding additional products that you should or shouldn’t combine with their herbicide.

Don’t Forget About Spreaders

There are three ways to disperse crabgrass killers. You can use a regular lawn spreader if the herbicide comes in powder form. This method is useful for broadcasting applications because even with a small lawn spreader, the dispersal pattern is wide.

You can also connect the garden hose to the bottle sprayer and set the desired PSI. Not all manufacturers offer this option, but those that do usually make their sprayer attachment compatible with standard garden hoses.

Finally, there’s the wand or comfort wand. Wands are useful for spot-on or precision treatments. The wand sends out a narrow but concentrated stream that’s easier to aim and control.

A Few Tips on DIY Crabgrass Killers

For a long time, people relied on vinegar solutions to kill crabgrass. It’s understandable as it’s a natural herbicide, and it’s unlikely to poison the waterbed. But, vinegar is non-selective. While effective against most weeds and crabgrass, it will also kill your lawn. You shouldn’t even use it for spot-on treatments.

Pouring boiling water on crabgrass is perhaps a bit safer than using vinegar. It will kill crabgrass and many weeds, but it can also damage your turf. There’s another reason why these two DIY remedies aren’t that popular anymore. You can’t use either for broadcasting applications, which renders them useless when crabgrass has spread over large patches of turf.

What’s the Most Efficient Active Ingredient in Crabgrass Killers?

After MSMA became obsolete, quinclorac has become the most widely used active ingredient in crabgrass killers. Almost all retail-grade herbicides have it due to its rather selective nature and low impact on regular turfs. That said, it’s not always easy to use, hence the need to follow label instructions very carefully.

Dos and Don’ts of Using Crabgrass Killers and Other Herbicides

Assuming you haven’t treated your lawn for crabgrass and other weeds, here are some things that you should know. It’s important to never apply treatment after cutting your lawn. Doing so will limit the grass and weeds' ability to absorb the herbicide.

Never use more product than indicated on the label. Note that some crabgrass killers will be labeled for sequential application or long-term treatment. It won’t do you any good to spray double the amount upfront since the crabgrass won’t absorb all of it. On the contrary, this could hurt the surrounding lawn even more.

It’s also important to avoid watering your lawn or even seeding it after applying a treatment. Different herbicides will have different rainfall proofing rates, as in how long it takes before it’s safe to get the solution wet.

When it comes to seeding or using fertilizer, again, you’ll have to wait. But, in most cases, it may take at least two weeks before you can safely reseed and fertilize treated areas.

Kill Your Crabgrass Before It Gets the Better of Your Lawn

Picking the best solution among crabgrass killers for your lawn is not an art or science. If you remember the crucial tips in this article, then reading a label should be very enlightening the next time you do it.

Whether you pick a crabgrass killer from this list or not, you now have the knowledge to spot fake advertisements or highly dangerous herbicides.

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