Getting rid of weeds can be tough.
Done by hand, it’s back-breaking and time consuming work. That has to be repeated again and again throughout the year.
Using weed killer makes the job a lot quicker and easier.
There’s just one problem:
Most weed killers will poison your grass as well as the weeds.
So finding the best weed killer for lawns is essential if you want to avoid that brown and burnt look.
In this buying guide, we’ll show you our favorite products. And we’ll take a look at the important things you have to consider when using weed killer on your lawn. So you can keep it looking lush, green, and weed free.
Let’s dive in.
Our top choices at a glance:
- PBI/Gordon’s Speed Zone Lawn Weed Killer – Top Choice Overall
- Southern Ag 2,4-D Amine Weed Killer
- Ortho Nutsedge Killer for Lawns Ready-To-Spray
- Spectracide Weed Stop For Lawns Plus Crabgrass Killer Concentrate
- Bonide Ready To Use Chickweed, Clover and Oxalis Weed Killer
- T-Zone Turf Herbicide
- Ortho Weed B Gon Weed Killer for Lawns Concentrate
- Espoma Organic Weed Preventer
- Roundup for Lawns Ready to Spray
- Scotts Halts Crabgrass & Grassy Weed Preventer
The Best Weed Killer For Lawns: Reviews
All 10 of the products reviewed are worth taking a look at as some are specifically designed to deal with certain weeds. You can find the reviews of each product below.
PBI/Gordon’s Speed Zone Lawn Weed Killer
This product is one of the fastest weed killers for lawns with results usually visible within several days.
The main active ingredients are 2,4-D, dicamba, mecoprop-p acid, and carfentrazone-ethyl. This formula contains both contact and systemic herbicides. So it immediately attacks the weed from the outside and kills it to its roots internally over a couple of weeks.
As it’s selective, it’s specially formulated to get rid of difficult weeds such as plantain, clover, dandelions, and creeping charlie. As well as many other broadleaf lawn weeds.
And although it’s mostly used for killing existing weeds, it also contains ingredients that can prevent broadleaf weeds from sprouting.
It does all this without harming your lawn. But, you have to be careful what grass you use it on. The product is recommended for:
- Perennial ryegrass
- Kentucky bluegrass
But it’s not for use on St. Augustine grass.
If your type of grass is not on the recommended list it might still be okay to use. But you should test it on the fringes of your lawn first to make sure.
Another thing to be careful of is not to overapply it, as some customers have reported damage when they haven’t followed the instructions properly.
The 20 fluid ounce bottle contains enough concentrate to cover as much as 18,200 sq. ft. of lawn when diluted. So most people can get years of use from it.
Southern Ag 2,4-D Amine Weed Killer
This systemic weed killer deals with most broadleaf weeds including dandelions, hawkweed, clover, and plantains. And there are even customer reports of it killing crabgrass.
And as it kills plants to the root, it also prevents them from growing back quickly.
Results with this weed killer become apparent after a few days as the weeds start to wilt and brown. But it often takes around 2 weeks to completely kill affected plants.
It’s great to use on lawns because it’s highly selective and doesn’t damage most grasses. There are exceptions though, and it’s recommended to be careful about using it on St. Augustine grass. However, some customers say that it just causes its growth to be temporarily stunted.
And you should be careful to follow the instructions. As mixing it up too strong or over-applying it to an area will cause the grass to die. You’ll find the mixing instructions on the label.
When diluted properly, the 32 oz bottle covers 20,000 sq. ft. of lawn. Making it an economical and long lasting product for most users.
Ortho Nutsedge Killer for Lawns Ready-To-Spray
Anyone who’s had a nutsedge infestation on their lawn knows just how hard it can be to get rid of this stubborn weed.
But thankfully, this product by Ortho is specially formulated to selectively kill nutsedge. Along with over 50 of the most common and tough weeds. Including wild violet, creeping charlie, dandelion, purslane, spurge, dollarweed, and plantain.
And while it’s not advertised as being good for crabgrass, there are reports of multiple applications doing the job.
One of the great things about it is that you can use it safely on a wide variety of Northern and Southern turf grasses.
And it’s easy to use. It comes in a ready to spray bottle, so you don’t have to do any mixing yourself, or have any need for a spraying tank.
- First, you connect the sprayer on the top of the bottle to the hose.
- Then turn on the water.
- Flip the tab to ON.
- Then start to walk slowly up and down your lawn while spraying evenly on the grass and weeds.
To get the best results, you should use it when the weeds are actively growing but less than 3 inches high.
Nutsedge starts to turn brown and yellow after a couple of days. And after a week or two it’s usually totally brown and dead.
Sometimes it takes more than one application to get the job done. So make sure you have enough left in the bottle to spot treat any problem areas. There’s a clear stripe on the back that shows the amount remaining.
Each bottle contains enough weed killer for you to cover 5000 sq. ft. when it’s connected to your hose.
Spectracide Weed Stop For Lawns Plus Crabgrass Killer Concentrate
This product is great for controlling over 250 types of broadleaf weed. Alongside the advertised crabgrass, it also deals with dollarweed, spurge, dandelion, yellow nutsedge, chickweed, foxtail, and clover.
It kills weeds to the root, and results are visible in as little as 8 hours.
The formula contains 2,4-D, quinclorac, dicamba, and sulfentrazone as its active ingredients. It’s mostly a post-emergent weed killer that works best when it totally covers the growing plant. But it also has a residual action in the soil that prevents the growth of some weeds, giving it pre-emergent properties as well.
It’s safe to use on most grass types with one exception: like many weed killers, it’s not advised to use it on St. Augustine.
And there’s another thing to take note of:
It’s most effective to use this weed killer when the daytime temperature is between 45 and 90°F. But don’t use it when temperatures are higher or it can damage your lawn. And you shouldn’t use it on bermudagrass at temperatures over 85°F. Wait until temperatures cool later in the day if summer temperatures regularly exceed this.
You should also apply it on a dry day, but it’s rainfast within 3 hours and after that, the rain won’t wash it off.
The 32 oz. bottle of concentrate can cover 5000 sq. ft. of grass when diluted to instructions.
Bonide Ready To Use Chickweed, Clover and Oxalis Weed Killer
This easy to use product is ready to spray when it arrives. So there’s no diluting or mixing. The 1 gallon bottle has a hand pump sprayer that makes it ideal for spot treating troublesome areas.
It successfully controls over 100 different broadleaf weed species. Including chickweed, ground ivy, clover, wild violet, dandelions, and oxalis. But, it’s not very effective on crabgrass.
This is a systemic weed killer, and the time it takes to work its magic tends to vary. Some weeds, like dandelion, show quick results within 24 hours and are dead after 1 spray. Whereas others, like oxalis and clover, can take several days or more to show results. Stubborn and persistent weeds sometimes take 2-4 weeks to die.
For the best results, it’s important you make sure the weeds are properly soaked. And don’t mow your lawn for a couple of days before and after use.
It’s safe to use on lawns. But, like many broadleaf weed killers, it’s not suitable for use on centipede grass or St. Augustine grass.
T-Zone Turf Herbicide
This product has a reputation as a powerful weed killer that works efficiently to control tough and persistent weed species. These include white clover, dandelions, spurge, creeping charlie, oxalis, wild violet, yellow nutsedge, and clover.
One Application is sometimes enough to kill all the weeds on your lawn. And they usually don’t regrow quickly.
It contains 4 main active ingredients that combine their effects together for maximum weed control: triclopyr, sulfentrazone, 2,4-D, and dicamba.
These systemic and post-emergent herbicides slowly kill it over a period of 2-3 weeks. Dicamba will also kill broadleaf weeds before they have sprouted.
And because they’re selective, they won’t usually damage your lawn. But there are exceptions, and it’s not suitable for use on all grass.
These grasses are listed as ones to avoid:
- St Augustine
The herbicide is rainfast after 3 hours and if you wait 3 weeks then you can reseed the area again.
Ortho Weed B Gon Weed Killer for Lawns Concentrate
Ortho Weed B Gon kills over 250 broadleaf weeds to the root. Including common species such as dandelions and clover, leaving you with a lush and healthy lawn.
Within hours results are noticeable. First, the leaves of the weeds start to curl. Then they turn brown and wilt after about a week. Death usually follows after 2-3 weeks. Although certain species of weeds may need a second application before they’re completely eradicated.
It’s designed for use on Southern and Northern lawns. The company states that the following grasses are all safe to use it on:
- St. Augustine (most types)
But, it’s not for use on St. Augustine Floratam lawns.
For other types of grass not mentioned in the list above, it’s best to do a small test on an inconspicuous area first before spraying the whole lawn.
The company guarantees it won’t harm your lawn if you follow the instructions on the bottle. Which means also being careful not to use it when temperatures are over 85°F.
For easy use with a hose, you can attach it to the Ortho Dial ‘N Spray Hose End Sprayer. Or you can mix it with water and use a tank sprayer.
Espoma Organic Weed Preventer
Espoma is a pre-emergent weed preventer that uses corn gluten meal as its main ingredient. When the granules are sprinkled and watered in it raises the level of protein in the soil, inhibiting the growth of seeds.
For this reason, it’s no good for existing weed problems. And it requires planning to make sure you apply it at the right time for it to work.
It’s recommended to use it once in early spring and then again in the fall after the hot summer temperatures start to cool down. Each time it remains active for about 6 weeks. Sometimes you’ll still have a small amount of weeding to do, but Espoma aims to keep the bulk of the problem away.
It also contains slow-release nitrogen which fertilizes your soil and helps your lawn to grow green and lush. Just don’t plan on planting seeds in the treated area for at least 6 weeks after use, because it will inhibit them as well. But it’s fine to use around established plants without fear of harming them.
One of the best things about this product is that it’s organic and natural. So you don’t have to worry about exposing your children and pets to any chemicals when playing on your lawn.
A 25 lb bag can cover 1,250 sq. ft. of lawn.
Roundup for Lawns Ready to Spray
Roundup for lawns is a specially formulated version of this well-known brand that’s designed to kill weeds on Southern lawns without damaging the grass.
This means it’s ideal for using on grasses that many other products will harm, including:
- St. Augustine (including Floratam)
Just be careful not to use it when temperatures are over 85°F to keep your grass healthy.
It kills over 90 different lawn weeds to the root, helping to prevent regrowth. Including hard-to-kill species such as dollarweed, yellow nutsedge, dandelion, and clover.
One application will kill most weeds within 10-14 days. But it’s recommended to make a second application for badly infested areas.
This is a ready to spray product, so there’s no need for dilution. And it comes with a wand for application that makes it easy to spray the herbicide over your entire lawn. Make sure to use it when weeds are in their early growth stages for the best results.
There’s enough weed killer in the bottle to cover 6000 sq. ft. of lawn, and it’s rainproof in about 4 hours.
Roundup offer a full money back guarantee if you’re unsatisfied with the results of this weed killer.
Scotts Halts Crabgrass & Grassy Weed Preventer
This is the second of our recommended pre-emergent weed preventers on this list. This means you need to use it at the right time to get the best results, because it won’t do anything for weeds that are already growing.
Instead, it stops weed seed germination when it’s applied to the ground in early spring. If you’re trying to prevent crabgrass, add it a couple of weeks before temperatures become warm enough for germination.
This is usually after you’ve had the first week of 65+ temperatures that warm the soil. Crabgrass germinates at temperatures over 55°F, so you can use a soil thermometer if you want to be precise.
You can also apply it again in the fall to prevent the germination of poa annua, chickweed, and henbit. But don’t apply it more than two times per year, and give it at least a two month gap between applications.
Once you’ve applied it and watered it into the soil the weather won’t affect it’s performance, whether it’s rain, snow, or shine.
It’s safe to use on all types of grass except for dichondra and bentgrass. And it’s also not recommended for use around ornamental flowers and shrubs.
Unlike Espoma, this is not an organic product. Instead, it uses the chemical pendimethalin.
Each bag of the granulated product contains enough to cover 15,000 sq. ft.
How To Choose A Lawn Weed Killer
There are many weed killers available covering every type of weed situation. But many of them are not suitable for lawns.
We’ve recommended our favorites above. But if you find yourself looking at other products online or in the store there are a number of things that you need to consider to make the right choice:
Is It Selective?
Some of the most popular herbicides kill all plant life, grass included, and have to be used with great care around your garden. They are known as non-selective weed killers. They are very difficult to use safely on your lawn without collateral damage and are best avoided.
Instead, you should choose a selective weed killer. These are usually formulated to kill broadleaf plants, and certain specific types of grass, and leave common lawn varieties alone.
But you’ll still need to check exactly what you can and can’t use them on.
Some of the best weed killers are good to use on Southern grasses. Whereas others will cause them harm. In particular, St. Augustine can be tricky as most weed killers will damage it.
Is It Pre-emergent Or Post-emergent?
Have you got a lawn that’s full of weeds?
If so, then you need a post-emergent weed killer that can kill plants that are already growing.
Or are you preparing for the battle in advance and trying to stop them from growing in the first place?
If that’s the case, then you’ll need a pre-emergent weed killer that can go into the soil and stop seed germination.
If it’s a pre-emergent that you’re after, remember that you won’t be able to reseed the area until after its effects have expired. Often between 6-8 weeks. Why? Because it will stop your grass seed from germinating as well.
Does It Have A Residual Effect?
Some weed killers remain in the soil and have a residual effect that can prevent further growth in the area. Herbicides that remain active for a long period of time are also called persistent.
Non-persistent weed killers that don’t have a residual effect will allow weeds to grow back again. Often as a result of seeds or root structures that have remained in the soil.
Contact Or Systemic?
Depending on how they attack plants, you can split after weed killers into two different types: contact and systemic.
As the name suggests, contact weed killers affect any parts of the plant they come into contact with. But only those parts. So when using them you need to make sure that the weeds are fully wet.
The results are quick. But contact weed killers are often non-selective and will poison the grass on your lawn as well.
Systemic (or translocated) weed killers are taken inside the plant through the leaves or roots. Once inside, the plant’s circulatory system carries them to every part to do their damage.
This is a slower method of killing the plant, and it often takes 2-3 weeks to do the job. But the great thing is that it kills them all the way down to the root, preventing them from regrowing. This makes systemic herbicides excellent for dealing with perennial weeds with developed root systems. They include the often used chemicals glyphosate and 2,4-D.
What Type Of Weeds Do You Have On Your Lawn?
Some of the best weed killers are formulated to target a particular type of weed.
So it’s a good idea to identify the weed that’s growing on your lawn before you buy.
Here’s a quick guide to help you get started:
Broadleaf weeds typically have wide leaves with large visible veins, and sometimes flowers.
It’s common to find them growing in thin areas of your lawn where your grass is struggling. They find it easier to thrive in soil that’s poor in nutrients, and stand out because their appearance is so different from your grass.
This category includes many common types of weeds such as dandelions, oxalis, spurge, clover, plantain etc.
If you’re living in Northern US, then you’re probably accustomed to seeing all of these. If you’re from Southern US then spurge, plantain, wild onion, wild garlic, and clover tend to be the most common broadleaf species you’ll find.
Broadleaf weeds don’t all respond to the same chemicals. So weed killers targeting them usually have a number of active ingredients.
Grassy Weeds & Crabgrass
Crabgrass, dallisgrass, creeping bentgrass, quackgrass, and goosegrass are common examples of grassy weeds that you might find on your lawn.
In Northern US it’s common to find crabgrass, creeping bentgrass, and quackgrass. Whereas in the Southern US goosegrass and dallisgrass are common lawn invaders. But it’s also not unusual to find crabgrass, creeping bentgrass, and quackgrass in warm season lawns.
Crabgrass, in particular, can be difficult to control. It’s a big, gangly weed that looks somewhat similar to normal grass. It dies each year when the weather gets cold. But each mature plant leaves behind thousands of seeds that remain dormant. In the spring they germinate when the soil temperature heats up over 55°F.
The best way of controlling it involves using pre-emergent and post-emergent weed killers. By laying down a pre-emergent weed killer in early spring you can prevent the seeds from germinating.
But this might not be 100% effective, so keep a careful eye for any that do appear and spot treat with a post-emergent weed killer. You can get weed killers that are specially formulated to control crabgrass.
How to Apply Weed Killer to Lawns
One of the easiest methods for spot treating a small area is to use a spray bottle after diluting the herbicide with water.
However, if you have a large area to cover it makes more sense to use a spray tank with the best lawn weed and grass killer. You can then walk up and down your lawn and quickly cover the whole area. Some bottles of weed killer concentrate come with a specially designed applicator that you can attach to your hose, making the process even quicker and easier.
Once your weed killer is ready, one application is often enough. But be careful not to over-apply it. Too much lawn herbicide can sometimes cause injury to your grass. Even with the best weed killer for grass that’s designed for lawn care.
You should also avoid using them during drought conditions, as grass that’s very dry can be damaged by the chemicals.
Another useful tip is to make sure you’re applying it on a day without rain. Most weed killers will tell you how long it takes for them to be rainfast. But if it rains shortly after application then the weed killer will be washed from the plant before it has a chance to have a serious effect.
Many weed killers are not suitable for use when temperatures go above 85°F. So it’s important to read all the details on the bottle and use it appropriately.
Weed preventers often come in granules that are best applied to your garden using a push spreader.
Although chemical herbicides are designed for killing plants, you still have to be careful when using them around people and animals. Getting them on the skin or in eyes can cause irritation. And ingestion could lead to sickness as the chemicals are toxic.
A list of protective equipment to use can be found on the label of the bottle and is a worthwhile precaution to follow when using the best lawn weed spray.
It’s also advised to keep pets and small children away from the area while you are spraying. And only allow them back on the lawn after the length of time recommended by the product manufacturers.
Organic products are available for those who want to take the extra step of preventing exposure to anything harmful. But, these are often not as effective as the best chemical weed killers and they cost more.
This is particularly difficult for lawns, as post-emergent selective weed killers that won’t kill your grass are always chemicals. So weed prevention is the organic method of choice.
What Else Can You Try?
If weeds are infesting your lawn, but you don’t want to use a chemical weed killer, then here are some DIY methods that you can try:
Dig Them Up
Yes, it can be hard work. And that’s the reason most people buy a weed killer. But it’s a time-tested method for weed control. If your lawn is not too big, then regular maintenance only requires a small amount of work from time to time.
Spray Some Vinegar
Vinegar is a simple household ingredient that also happens to be a very effective contact weed killer. In fact, many commercial natural weed killers use it as the main active ingredient. Although a 20% acetic acid solution is often used rather than the 5% you buy in the store.
But it’s not perfect. The big drawback is that because it’s non-selective it will kill your grass as well. So you have to be very careful when using it.
It’s best used for spot treatment and you might still end up with a small amount of damage to your lawn.
Bring Out The Weed Whacker
There are also powerful tools that you can take to the problem. For example, weed whackers.
These devices are carried by hand and use a motorized plastic cord to trim the pesky weeds down to the same length as your grass, making them less conspicuous.
But they won’t completely get rid of them as they don’t affect the roots. So regular use is required because weed growth will continue.
It’s important to get the right type of weed killer to use on your lawn, because not just any product will do. Many weed killers are non-selective and will destroy your lawn unless you are very careful when using them.
So it’s best to look for selective weed killers that are made to target the sort of weeds that you are struggling with. Then you can have a weed free and healthy lawn.
Our recommended list of the best weed killers above contains products that are specially formulated to deal with all the common broadleaf and grassy weed types that often cause problems.
So, what is the best weed killer that won’t kill grass?
If you’re looking for the best broadleaf weed killer for lawns, then consider trying Gordon’s Speed Zone. It’s a powerful liquid weed killer with many satisfied users.
If it’s crabgrass that you need to eradicate, then Spectracide is the most effective weed spray for lawns that can take care of the job while being safe for grass.
And if you’re looking for an organic product that will prevent weeds from growing on your lawn, then Espoma is well worth trying.