The Best Weed Killer – Buying Guide & Reviews

The struggle is real.

Whether it’s lawns or flower beds. Driveways or patios. Fence lines or foundations.

Weeds are persistent, and they’re here to take over.

Trying to get rid of them by hand can be back-breaking work. Not to mention impractical over large areas of land.

So you need a weed killer. And you need one that does the job with a minimum of fuss.

We’ve looked at all the top products on the market to find the best weed killer for every situation.

We’ll explain exactly what they do and show you the one that’s the best fit for you.

Let’s get started!

How To Choose The Right Weed Killer

Spraying herbicide

Did you know, that weed killers actually come in many different types?

And unfortunately, there isn’t a ‘one size fits all’ solution.

Where you want to use it and the stage of weed growth will decide the type you need to get the best results.

Let’s take a look at the main things to consider so you can make the right choice.

What’s The Selectivity?

If you’re growing things you want to keep, you’ll need to make sure you choose a weed killer with the right selectivity.

Selective weed killers only kill the weeds, without killing nearby plants.

Whereas non-selective weed killers kill all plant life they’re applied to.

Use Advice:

Use a selective weed killer to kill unwanted weeds such as dandelions without damaging your lawn. Or to kill weeds in flower beds or vegetable gardens.

Use a non-selective weed killer on the weeds that spring up between cracks on your driveway, patio, or paving stones.

But, be careful to read the advice on the bottle. As some selective products will still damage certain grasses.

You can also get weed killers that only target grasses, while leaving broadleaf plants alone.

Check The Emergence

Are you trying to get rid of weeds that are busy taking over your garden?

Or do you want to strike first this year and stop them from taking root?

Depending on your answer you’ll need a different type of product.

A pre-emergent weed killer prevents the growth of weeds. Add it to soil two or three weeks before germination to prevent them from appearing.

But you’ll need to use a post-emergent weed killer on weeds already infesting an area. Apply it directly to the plant.

What’s The Persistence?

This refers to the duration the weed killer remains active preventing further growth.

We describe weed killers with long-lasting action as persistent.

Held in the surface of the soil, sometimes for several months, they prevent weed seeds from germinating. But, the treated area of ground must be undisturbed otherwise the effect is reduced.

Non-persistent weed killers have a shorter duration of action, and weeds will grow back again after use.

Contact v Systemic

There are two different ways that weed killers attack their target:

Some kill the weed as soon as they make contact with it.

While others, known as systemic (or translocated) herbicides are absorbed by the plant. They are then transported through its circulatory system from the tips of its leaves to its roots, attacking it inside.

Use Advice:

Systemic weed killers take longer to deliver results. But they kill the whole plant. This makes them very good for dealing with perennial weeds with developed underground root systems.

As contact herbicides only kill the part of the plant they touch, it’s important to cover as much of it as you can. Because otherwise, you might only kill half of the weed while the other half continues to live. Sometimes, it needs repeated doses to get the job done.

Contact herbicides are good to use for annual weeds. Or for perennial weeds only recently germinated, without the time to develop a large root system.

One advantage of using them is that accidental spraying on nearby plants will only leave a small amount of damage. Compared to systemic weed killers that might kill the whole plant.

The Top 10 Best Weed Killers

If all the above sounds a lot to consider, don’t worry, we’ve made it easier for you.

The table shows our top recommendations out of the brands reviewed for each type of use. You can find our full review of all 10 selected products below.

Compare-N-Save Concentrate Grass & Weed Killer

compare n save

One of the most popular options on the market, Compare-N-Save is a non-selective weed killer. Which means it kills everything.

Annual or perennial weeds? Check

Unwanted plants? Check

Brush and vine control? Check

You name it, Compare-N-Save will eradicate it.

This is thanks to its 41% glyphosate formulation.

It’s ideal for removing stubborn weeds from paths and driveways. And those wild areas along property fences that can take all day to tame by hand.

You can also use it around vegetable gardens and flower beds. But be careful to avoid the spray drifting unnoticed onto areas you don’t want to treat. This stuff is powerful and unforgiving.

For this reason, it’s also advised to keep it away from your lawn.

This is a post-emergent weed killer. So it kills the weeds you already have, but it won’t linger in the soil for a long time preventing plant growth.

So after using it to clear an area of land, you can use the soil for planting within a couple of weeks. The label on the bottle gives detailed replanting instructions for fruit and vegetables.

And this product goes a long way. You just need to mix a small amount of the concentrate with water for it to do its work. With 1 bottle making up to 85 gallons of diluted, but highly effective, weed killer.

But, if speed is important to you then it’s best to look for another product.

Why? Because this is a slow weed killer. It works by killing plants systemically all the way down to their roots. And although it’s common to see some yellowing after several days, it’s not unusual to wait a couple of weeks for the plants to die.

Apply it on a sunny day with no rain and it takes up to two hours to dry. After that, the company claims it’s safe to let your pets roam around on the sprayed area.

It’s very similar to Roundup, containing the same glyphosate active ingredient. And it’s usually available as a cheaper alternative. But it’s worth knowing that despite this, some people still prefer Roundup.

Pros
  • Kills all types of weeds
  • Kills to the root so they don’t grow back quickly
  • Great value
Cons
  • Works slowly
  • Because it kills everything be careful what you apply it to
 

Roundup Weed & Grass Killer Super Concentrate

Roundup

If you need something with extra strength that can tackle even the most stubborn weeds, then this might be just what you’re looking for.

RoundUp is a well-known and appreciated brand that’s developed a strong reputation for the effectiveness of the product. This extra strength weed killer contains 50.2% glyphosate.

It’s designed for use in a tank sprayer and works superbly to keep weeds under control over large areas.

As it’s a systemic weed killer, the weeds are killed all the way to the root. First starting to yellow and wilt between 2-4 days with death coming within 1-2 weeks.

It’s perfect for use on driveways, patios, walkways, gravel beds, and along fences and foundations.

Most weeds can be eliminated with just 1 or 2 applications. Although there are reports from customers that it can take up to 5 or 6 treatments to kill the likes of nutsedge.

But be careful using it around any plants that you want to keep. Because it’s non-selective, you risk killing any plants that it gets on. And this extra strength formula takes no prisoners.

The concentrate is easy to prepare and use. It comes in a large 1 gallon bottle that can make up to 85 gallons when diluted at 1.5 oz per gallon of water.

Even stronger concentrations of 2.5 oz per gallon, for those really stubborn and resistant areas, will see this last a long time for most users. Making it one of the most economical ways to treat large areas of weeds.

You should apply it to selected areas when the weather is dry. And it’s fast drying, usually within 30 minutes. After this, watering or rain doesn’t reduce its effectiveness.

Is this worth buying over the more budget conscious Compare-N-Save?

Well, that’s up to you. It’s a stronger product. And although most are satisfied with Compare-N-Save there are reports from users who have switched back to Roundup because they found it did a more effective job. But they are very similar products using the same active ingredient.

Pros
  • Kills all weeds
  • Strong concentration
  • Kills to the root
Cons
  • Damages lawns
  • Slow acting
 

Southern Ag Amine 2,4-D Weed Killer

2,4-D Amine

This selective, systemic weed killer is ideal for using in a variety of locations. You can use it to treat lawns, pastures, fence lines, and rangeland.

And not only will it kill the weeds already growing, but it also stops them from growing back.

It works quickly, with some starting to die within days. But, it can take up to 2 weeks on some broadleaf weeds, such as poison ivy, to see its full effect.

While it’s generally fine to use on your lawn, there are some words of caution:

Some people report that it does at least temporarily stunt the growth of St. Augustine and slows down bermudagrass when it’s applied. But with a full recovery after.

And be careful when diluting it. Some customers say that it will kill the lawn if you mix it up too strong.

The 32 oz bottle of Southern ag 2,4-d amine weed killer contains enough concentrate to cover 20,000 sq. ft. when it’s diluted.

Pros
  • Selective weed killer that can be used on lawns
  • Kills a wide variety of broadleaf weeds
  • Stops Weeds Regrowing
Cons
  • Have to be careful when using it on some grasses
 

PBI/Gordon’s Speed Zone Lawn Weed Killer

Gordon's Speed Zone

If you’re looking for a specialist product to treat your lawn, then you don’t have to look any further than Gordon’s.

This selective weed killer is great for getting rid of stubborn weeds such as clover and creeping charlie. And it effectively treats many other hard to remove broadleaf weed species. The dandelions don’t stand a chance!

It does all this without harming your grass…as long as you’re careful.

Because, unfortunately, it’s not suitable for all grass types.

The following are all recommended to use it on:

  • Kentucky bluegrass
  • Perennial ryegrass
  • Fescues
  • Bermudagrass
  • Zoysiagrass

But, it can harm the popular St. Augustine.

And some customers have reported that you have to be careful not to over-apply or it can brown your grass.

It comes in a 20 fl. oz. bottle. And when diluted to the instructions given this is enough to cover from 13,300 to 18,200 square feet of lawn, depending on the strength of weed killer you require.

With the key active ingredients it contains in its formula being 2,4-D, mecoprop-p acid, dicamba, and carfentrazone-ethyl.

And because it’s fast-acting, with results often noticeable in hours, you can clear away weeds and reseed within a couple of weeks.

However, some difficult to remove weeds, such as plantain can take up to a week or more to kill off. With 2 or more applications sometimes needed to eradicate it.

Pros
  • Kills a large variety of lawn weeds
  • Fast-acting
  • Very effective
Cons
  • Not safe for all types of grass
 

Preen Garden Weed Preventer

Preen

Are you looking to stop weeds from growing in your garden this year?

If so, then this pre-emergent and selective weed preventer from Preen could be just what you’re looking for.

It successfully prevents all types of weeds from growing. But importantly, unlike some of the more indiscriminate weed killers like Roundup, it’s safe to use near flowers and shrubs. This is because it doesn’t kill existing plants.

Instead, when applied to the ground before weeds appear, it bonds with the soil to form a no-go zone for up to 3 months that stops them from germinating.

But, this means all weeds and grasses must be removed from the ground you are treating before you apply it if you want a weed free garden.

It’s designed for safe use around over 200 different common species of flowers, shrubs, trees, and vegetables. However, it’s not recommended for use on lawns.

It won’t build up in your soil, but it also doesn’t easily wash away. And nor will it leach into groundwater.

For best use, try spreading it in early spring before weeds appear. And then top up in the summer and fall.

The company says that it’s safe to use if you have pets.

Pros
  • Safe to use around vegetables, flowers, and shrubs
  • Easy to use
  • Very effective weed prevention
Cons
  • Doesn’t get rid of weeds that already exist
 

Bayer Advanced All In One Lawn Weed & Crabgrass Killer

Bayer Advanced

Bayer Advanced is a post-emergent weed killer that kills over 200 common broadleaf weed species on contact, including clover and dandelion. As well as grassy weeds like the crabgrass advertised in the product name.

But, although it’s selective and designed for weed control on lawns, this type of weed killer does have its limitations. With the manufacturer specifically stating that it’s not for use on certain grasses such as St. Augustine, carpetgrass, and dihondra.

Its formulation contains 2,4-D, dicamba, as well as quiclorac (which helps to treat crabgrass). With the result that many common weeds are killed after just one application. While even quite heavy crabgrass coverage can be dealt with in 2 or 3 goes.

One really neat feature is that it contains a non-staining red marker that helps you see the areas you’ve already sprayed. After use, it quickly fades with the sunlight until it’s unnoticeable.

The product comes in a 32 oz bottle, which at the recommended use of 3.2 oz per gallon of water can give you enough to treat 5000 sq. ft. of your lawn. So for most people, a bottle will last a long time.

After application, it needs an hour to dry before it’s rainproof. Remember to always use it in the afternoon, after the morning dew has dried. Otherwise, water will dilute it and it won’t live up to expectations.

Pros
  • Non-staining marker makes sure you don’t miss any spots
  • Kills a wide range of common lawn weeds
  • Effective for crabgrass
Cons
  • Not good for all grass types
 

Ortho GroundClear Vegetation Killer

Ortho Groundclear

Are you looking for a powerful non-selective grass and weed killer that will tackle anything?

This product does exactly what it says on the bottle. Any area of ground that you apply it to is cleared of all plant life. It takes no prisoners.

Which means it’s no good for keeping weeds at bay around flower and vegetable beds in your garden. Or for treating lawns.

Instead, this is the nuclear option for when you want to remove everything and start again. But it also provides protection from weeds for up to 12 months. So don’t plan on anything growing on that ground anytime soon.

For this reason, it’s often best used  as a total vegetation killer for clearing weeds from drives, walkways, patios, and fence lines.

It contains two main active weed killing ingredients: 5% glyphosate and 0.8% imazapyr. Both of these are systemic and poison plants all the way down to the root.

But, although the weed killer is advertised as being fast acting, with results after 6 hours, there are mixed reports from customers. With many saying it takes several days to see an impact and longer for the full effect, which is typical of systemic weed killers.

However, there are some people who see it take effect overnight. Suggesting that depending on the weed you use it on you might need more patience than advertised.

As with other weed killers, you should apply when it’s dry. And this product is rainproof after 1 hour.

Pros
  • Kills almost all plants
  • Prevents weeds and grasses from regrowing for up to a year
  • Excellent for drives, paths, and gravel areas
Cons
  • Can’t be used on lawns or flower beds
 

RM43 43-Percent Glyphosate Plus Weed Preventer

RM 43

One of the strongest weed killers available on the market, RM43 contains 43% glyphosate and 0.8% imazapyr in its formulation.

In addition to those herbicides, it also includes a surfactant that helps it to evenly coat the surface of leaves without beading up and rolling off.

It works both as a pre-emergent and post-emergent weed killer. So not only can you apply it to stop new weeds from appearing. But you can also spray and kill existing weeds.

Because it’s a non-selective herbicide and will kill most things you apply it to, you have to be careful of using it near your lawn or garden

Instead, it finds its best use as a weed and grass killer when you have large pieces of land to clear, or areas around barns and buildings.

Other uses include parking areas, pathways, fence rows, and driveways. Or for spot control of weeds, vines, and brush. It’s even advertised as being effective for use on small trees.

Areas that are treated stay free of weeds for around a year. So it’s not great for using on any soil that you want to use for planting anytime soon.

This means that if you’re looking to kill everything on an overgrown lawn and then replant to start again, you’d be better off looking for a different weed killer.

Although it’s powerful, like most systemic weed killers that use glyphosate you’ll have to wait a while for its effects to kick in. 3-7 days is common, with 2 weeks needed to get the full job done.

A 1 gallon bottle of RM43 weed killer concentrate can be used to treat 17,297 square feet of land. And it dries and is rainfast within 2 hours. With no danger to animals after it’s dried according to the company.

Pros
  • Added surfactant to help it stick to the leaves
  • Powerful all-purpose weed killer
  • Persistent – prevents weeds from regrowing for 1 year
Cons
  • Slow to kill vegetation
  • Not to be used on lawns or around valued plants
 

Scotts Halts Crabgrass & Grassy Weed Preventer

Scotts Halts

It’s not hard to see why this product is such a popular choice for lawn care. When used correctly, it’s a highly effective and great value solution with long lasting effects.

It acts as a pre-emergent, preventing the germination of crabgrass and many other lawn weeds before they grow.

You can apply it in early spring to stop crabgrass. And you can apply it again in the fall to prevent the appearance of weeds like chickweed, henbit, and poa annua. Keeping your lawn weed free and looking beautiful all season long.

And one of the useful things about it is that unlike many other lawn weed killers, it’s safe to use on St. Augustine grass. However, it’s not for use on lawns of dichondra or bentgrass.

The only tricky bit for some people is getting the timing right when first using it. Put it down too early and it might lose some of its effectiveness. Whereas putting it down too late means it won’t do the job. This results in some customers complaining about the lack of results.

But it’s not as hard as it sounds, you just have to pay attention to it. Because crabgrass usually germinates over 55°F waiting for the soil temperature to reach 50-55°F is the key. And then you can make sure the soil is loaded in time to prevent crabgrass germination.

Remember that any thin or bare patches of soil will warm up sooner. So you’ll want to reseed these areas when it gets to early spring. Otherwise, you need to use the crabgrass preventer earlier on these areas than the rest of the lawn for full control.

Applying this weed killer is easy. It comes as dry granules containing the active ingredient pendimethalin. So you don’t need to mess around with any liquids or sprays.

First of all, start by mowing your lawn. And if there are any weeds already present you can remove them by hand, as this product won’t kill existing weeds. Then, after you’ve laid it down, water it in and leave your grass to dry. Once dried you can let your pets back onto the lawn safely.

One bag of the product can cover 15000 sq. ft. so it will last most people with an average sized lawn a long time.

Pros
  • Very effective at preventing crabgrass
  • Safe to use on most types of grass including St. Augustine
  • Long lasting weed prevention
Cons
  • Doesn’t kill existing weeds
 

Spectracide Weed Stop For Lawns

Spectracide

If you’re looking for a weed killer that gets rid of unwanted vegetation without damaging your lawn, then Spectracide Weed Stop is a strong choice.

It’s a selective herbicide containing a commonly used chemical called 2,4-D that kills weeds to the root. Formulated to deal with over 200 different types of weed, it kills all major broadleaf weeds, such as dandelion, clover, and chickweed.

And it’s easy to use. First, make sure that you mow your lawn. Then dilute and apply Spectracide using a sprayer. Make sure to wet each weed completely with the solution.

To get the best results, try using the weed killer spray in spring when the weeds are still small. And consider using it again for weed control in the fall—a time when many weeds germinate. Treating at this time of year also has the added benefit of reducing the number of weeds you can expect next spring.

If you have particularly stubborn weeds that haven’t died after about 3 weeks, then you might need to reapply the formula as a spot treatment.

The bottle comes with instructions for different weed types, as some of them do require a stronger dose to effectively get rid of them.

It can also be used for killing weeds between patio slabs, driveways, and walkways. But many customers report better success using non-selective weed killers such as Roundup and Compare-N-Save concentrate for those areas.

After applying the liquid herbicide, try to make sure the area remains dry for at least 6 hours after application. But after this, rainfall has no impact on its effectiveness.

Pets should be kept away while you are spraying Spectracide on the lawn, and only allowed back on again after it’s dried.

Its 40 oz volume is enough to make 40 gallons of effective weed killer, which can be used to control a 20,000 sq. ft. area. Which makes it pretty good value, even if you do have to sometimes apply this herbicide more than once.

Pros
  • A budget choice that won’t hurt your pocket
  • Kills weeds while leaving your lawn intact
  • Works on a wide range of weeds
Cons
  • Slow acting
  • Often requires multiple applications
 

Final Thoughts

Before choosing the best weed and grass killer it’s a good idea to think about exactly what you need it for.

Maybe it’s early in spring and you’re looking for weed poisons to stop weeds from appearing in your garden? If so, get a pre-emergent weed killer.

Are you looking to kill existing weeds? Then a post-emergent weed killer will be most effective.

Do you want to kill the weeds on your lawn, while leaving it healthy? Then you’ll need to purchase a selective weed killer

Or maybe you just need the strongest weed and grass killer you can find for weed control on your driveway? If so, then a non-selective weed killer that kills everything and keeps them away is the best choice.

Whatever your needs, the selection of the best weed killers above covers every possibility.

By making the right choice, and with careful application, you can look forward to a weed free year.


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