Keep Your Garden Weed-Free With These Effective Weed Killers (2024)

Our Top Picks

Our winner for best overall weed killer is this effective vinegar-based product from Green Gobbler. It's OMRI listed, meaning that the Organic Materials Review Institute has approved it as acceptable for use under the guidelines of the US Department of Agriculture's National Organic Program. This is a non-selective weed killer, so it is not for use in lawns; we put it to the test on a variety of weeds growing along a stone pathway, stairs, and sidewalk.

The product requires no mixing, and the container comes with a spray trigger head, which makes it basically pick-up-and-go. While we liked that convenience, we did find that the spray trigger tended to get stuck, meaning that we had to wait for a few seconds between each squeeze of the trigger. However, it was easy to target weeds without overspray drifting onto nearby desirable plants.

Upon spraying the weeds, the first thing we noticed was the powerful odor of vinegar, which persisted for more than 30 minutes after using the weed killer. The next thing we noticed was the quick results; within a few hours, the weeds were beginning to turn yellow, and by the next day, all of the sprayed weeds were dry and dead, with the exception of some dandelions. We gave those a second treatment, which did the trick. It was then very easy to remove the dead weeds by hand.

As we tested this weed killer at a home with pets, we especially liked that it's listed as safe for pets (and kids) to play and romp on the treated area once the spray is completely dry. The vinegar spray is effective on a wide range of annual and perennial weeds, as well as moss.

Use it to keep your walkways, pavers, driveway, and other landscaped areas free from weeds. You can also use it on mulched garden beds but do not allow the spray to come into contact with your planted greenery. Note that it should be used when there is no rain in the forecast for at least a day, as effectiveness will be reduced if it rains before the product works its magic.

_{Application Type: Spray︱Targeted Plants: Crabgrass, dandelions, and many other weeds︱Rain Resistance Within: Not applicable︱Primary Active Ingredient: 20% Vinegar}

This 16-ounce bottle can treat up to 3,200 square feet of lawn or other garden areas, making this a good choice if you have a lot of weeds to tackle and don't want to spend a bundle. While this weed killer is very effective against a wide range of common and pesky lawn weeds, including dandelions, clover, oxalis, spurge, and chickweed, we were most excited about its effectiveness in killing wild violet, as that was our biggest problem in the tested area.

We already had a garden sprayer on hand, but be aware that if you don't have a suitable tank or hose sprayer, you'll need to purchase one prior to using the weed killer. While the weed killer did work, it wasn't especially fast, taking six days before we saw noticeable results. We found that it took even longer to kill clover and ground ivy. Still, it eventually got the job done, and we had no damage to our grass.

This selective herbicide is safe for use on many common types of lawn grasses, including buffalo grass, all types of fescue, Kentucky bluegrass, ryegrass, and zoysiagrass. However, do not use it on Bermuda grass, St. Augustine, or centipede grass. Note that after application, the lawn should not be mowed for at least two days.

Once sprayed, the weed killer is rain-resistant within 6 hours. Be sure to keep pets and kids completely off the treated grass for at least 24 hours, and make sure the grass is dry before they walk or play on it. This herbicide should be applied when there is no wind, and the outdoor temperature is between 50 and 90 degrees.

_{Application Type: Concentrate spray︱Targeted Plants: Oxalis, chickweed, clover, and many other broadleaf weeds︱Rain Resistance Within: 6 hours︱Primary Active Ingredient: 8% Triclopyr, Triethylamine Salt}

We put this non-selective weed killer to the ultimate test, taking on Japanese knotweed, an invasive, fast-growing weed that is very difficult to eradicate. While we still had to pull as much of the noxious weed by hand as possible, we found that spraying this highly effective weed killer from Spectracide on the affected areas every week or so worked wonders in preventing recurrences of the knotweed. We also used the herbicide to kill other common weeds, including Creeping Charlie and poison ivy. In all instances, we were impressed with the weed killer's performance.

We sprayed the Spectracide along walkways and fences; it's also ideal for tackling weeds growing around or through patios, mulched garden beds, driveways, or along the house foundation. You'll start to see wilting and shriveling of smaller weeds as soon as 3 hours after drenching them with the herbicide, but it can take up to 2 weeks for large, tough weeds to perish. However, most weeds will eventually die right down to the root.

This is a concentrated formula that must be mixed with water prior to use. You'll want to apply it with a tank sprayer or other sprayer that makes it as easy as possible to target just the plants you want to kill, as this herbicide can and will kill off lawn grass and other desirable plants that it wets. If spraying near flowers or other small and delicate greenery, you can use a piece of plastic or cardboard as a shield.

If using the product to kill off weeds prior to planting new greenery, you can plant new shrubs, flowers, or trees within just 24 hours of application, but you'll need to wait a week before sowing seeds or laying down sod. Our only complaint about this effective weed killer is that it doesn't come with any sort of measuring device or funnel to make mixing with water prior to spraying easier. We do love that it's rain-resistant within just 15 minutes of application. For best results, spray when the air temperature is above 60 degrees; the warmer the weather, the faster the results.

_{Application Type: Concentrated spray︱Targeted Plants: Broadleaf weeds and grasses︱Rain Resistance Within: 15 minutes︱Primary Active Ingredient: Diquat Dibromide}

It can be difficult to eradicate weeds poking up through gravel, brick, or pavers. However, this effective herbicide from Ortho makes it much easier to tackle weeds growing in such hard-to-access spots thanks to its AA-battery-powered wand. We liked that the wand lets you choose from several different spray patterns so you can settle on the one best for your current needs. We found that the wide spray was best for handling weeds and grass growing in an area covered with river rock.

While we enjoyed the comfortable and easy-to-use battery wand, we were even more impressed with the effectiveness of this herbicide, which is OMRI-listed for organic gardening uses. We saw results within just 1 hour of drenching the weeds with the spray, although the largest weeds took a few days before they were entirely dry and dead. Even better, none of the treated weeds had begun to grow back by the end of our testing session.

The spray kills off just about any weed or grass, so be careful to prevent the herbicide from settling onto your lawn or onto desired flowers, vegetables, or shrubs. If killing weeds in a mulched garden bed, set the wand to the narrowest spray pattern and take care to only drench the weed, not the nearby plants. Ortho recommends using the product on a warm, sunny day without wind. Once the spray is dry, which is generally within 2 hours, it's rain-resistant and also considered safe for people or pets to walk or play in the treated area.

_{Application Type: Spray︱Targeted Plants: Broadleaf weeds and grasses︱Rain Resistance Within: 2 hours︱Primary Active Ingredient: 5.0% Ammonium Nonanoate}

Fighting lawn weeds can seem like a never-ending battle, but with this powerful selective herbicide from Southern Ag, you'll have the upper hand against even tough weeds like dandelions, ground ivy, thistle, clover, and spurge. This concentrated herbicide must be mixed with water prior to use and then sprayed with a tank sprayer designed to handle large volumes. While we found the product instructions to be a bit confusing—they are geared towards the commercial user, not residential users—once we figured out the ratio of herbicide to water, we were on our way and used the spray to eradicate dandelions crabgrass, purslane, giant hogweed, and clover.

While these were our primary weed types, the product does also kill most other broadleaf weeds. It's safe for use on almost all common lawn grasses except bentgrass, St. Augustine, carpetgrass, centipedegrass, and dichondra. Of course, you can also use it in other garden areas, such as around shrubs, flowers, or trees, but take care not to let the spray drift directly onto those plants; you only want to drench the weeds themselves.

We first started to see the treated weeds wilting and dying within two days of application. However, as quite a bit of rain fell during that time, it's possible that the herbicide's effectiveness was slightly reduced, although the manufacturer doesn't specify the amount of time needed for rain resistance. Still, all of the weeds we treated wilted, withered, and died, with no signs of regrowth during our testing sessions.

You should apply the herbicide on a warm day without wind and preferably without rain in the forecast for at least several days. Do not allow people or animals onto the treated lawn until the spray is completely dry, which could take up to 24 hours. If there are new or persistent weeds, you can reapply the herbicide 30 days later but do not use it more than twice a year.

_{Application Type: Concentrate spray︱Targeted Plants: Broadleaf weeds and grasses︱Rain Resistance Within: Not specified︱Primary Active Ingredient: Dimethylamine salt of 2,4-D-Dichlorophe noxyacetic acid}

Pulling weeds by hand is generally the best method in small flower beds, but for larger beds or when you are unable to get down in the dirt to manually remove weeds, we recommend this highly effective weed killer from Roundup. We used it in a garden bed and also in an area covered with landscape rocks that had several common varieties of weeds, including dandelions, clover, curly dock, and grass, and by the next morning, all of them were dry and dead right down to the roots.

The weed killer comes in a ready-to-use bottle with a very handy "Sure Shot" wand that made it super easy to pinpoint the weed we were spraying rather than nearby greenery. But to make it even more fail-proof, there's also a small protective plastic cup at the end of the spray wand; we found that by using the cup to cover the weed being treated, overspray to nearby plants was pretty much eliminated.

This is a non-selective herbicide, so it is not safe for use on lawns. However, it would be ideal for killing weeds sprouting between pavers, along fences or foundations, in mulched garden beds, around trees, or in other areas where it's important to protect nearby surfaces from the herbicide spray.

According to Roundup, the weed killer is rain-resistant a mere 10 minutes after application, but do not let people or animals into the treated area until at least 24 hours have passed and the spray is completely dry. For best results, use the herbicide when the air temperature is between 60 and 85 degrees.

_{Application Type: Spray︱Targeted Plants: Broadleaf weeds and grasses︱Rain Resistance Within: 10 minutes︱Primary Active Ingredient: Glyphosate}

In the battle against weeds, it can be most effective to prevent them from sprouting rather than dealing with them once they are actively growing. For that, you need a pre-emergent product like this highly effective option we tested from Preen. Note that it will not kill weeds that are already above the ground; you'll need to first pull those manually or use a post-emergent weed killer before applying the Preen. We applied this granular product along a driveway and in a garden bed that had been cleared of obvious weeds.

The Preen was very easy to apply; we sprinkled it across the ground, following the package directions for coverage. We had rain shortly after application, but if there's no rain in your forecast, then you'll need to water the treated area so the granules can begin to dissolve. Once watered into the soil, it won't wash away with further rain or watering.

The manufacturer claims that the product will continue to work for up to 3 months. While we can't yet vouch for that length of time, we observed no new weed growth in the treated area over the two-week testing period. In contrast, the control area, which was not treated, experienced significant weed growth during the same period. The weed preventative is effective against many common weeds and grasses, including purslane, foxtail, and crabgrass.

This isn't for use on lawns, but it's a great option for other garden areas, including vegetable gardens, flower beds, underneath trees and shrubs, atop mulch, or along hardscaped areas where you don't want weeds to sprout. It should be applied when the existing plants are dry, so it won't stick to their leaves; you want it to drop on the ground. However, you'll want to sweep it off concrete or other hard surfaces, as it can stain those materials.

_{Application Type: Granular︱Targeted Plants: Many broadleaf weeds and grasses︱Rain Resistance Within: Not applicable︱Primary Active Ingredient: Trifluralin}

If you're looking for a natural solution for pesky weeds sprouting up in walkways or even in planted areas, including garden beds, then we recommend this OMRI-listed grass and weed killer from Sunday. Its active ingredient is an herbicidal soap that dries out greenery upon contact, quickly leading to the death of the weed. In fact, you should start seeing wilting and shriveling within just 20 minutes of application, although it can take longer for the weed to fully die. Note that it's a non-selective weed killer, though, so it's not for use on lawns.

This is a ready-to-spray product that comes in a container with a battery-powered wand sprayer that makes it easy to pinpoint just the weeds you want to eradicate, not the nearby greenery you want to preserve. It's effective against many common weeds, including plantain, mustard, thistle, dandelion, annual bluegrass, pigweed, and mallow. It also kills mosses, algae, and lichens. It won't stain bricks, concrete, or other nearby hard surfaces, but you should still aim to produce as little overspray as possible.

For best results, apply the spray on a day without wind and air temperatures between 50 and 85 degrees. Once 3 hours have passed, it's rain-resistant. You'll need to reapply it every few weeks throughout the active weed-growing season. While this is an organic herbicide, it is still important to keep your pets and kids off the treated areas until the spray is completely dry.

_{Application Type: Spray︱Targeted Plants: Many broadleaf weeds and grasses, algae, lichen, moss︱Rain Resistance Within: 3 hours︱Primary Active Ingredient: Ammoniated soap of fatty acids}

Crabgrass, more properly called Digitaria sanguinalis, which is known for its somewhat crab-like appearance, is one of the tougher weeds to eradicate. While we didn't personally test Preen's Crabgrass Control, our research indicates that this is a potent weapon in your lawn-care program.

Like other Preen products, this is primarily a pre-emergent, meaning that it prevents the crabgrass seeds from sprouting. That's by far the best method for handling this aggressive weed, but never fear; even if you miss that window, Crabgrass Control also helps to kill crabgrass that's already growing, as long as you catch it early enough. While it won't kill dandelions, it also effectively suppresses or prevents the growth of many other common lawn weeds, including spurge, purslane, henbit, foxtail, and chickweed.

You'll need to apply this granular weed killer with your lawn spreader. It's safe for use on almost every type of popular lawn grass, even St. Augustine. Follow the package directions for the appropriate setting on your spreader, and you should have no issues with burns to your grass. Spread it across dry grass and then water it in well for the best results. Ideally, you should apply the product in early spring so you can catch the crabgrass before it sprouts, but it can also be used a second time in the fall if needed.

_{Application Type: Granular︱Targeted Plants: Crabgrass and many other broadleaf weeds and grasses︱Rain Resistance Within: Not applicable︱Primary Active Ingredient: Dithiopyr}

Final Verdict

If you want a highly effective yet organic weed killer, then our top recommendation is Green Gobbler 20-Percent Vinegar Weed & Grass Killer. In our tests, it quickly withered and killed sprayed weeds, and it can be used in many different areas around the garden. However, if you need a weed killer that’s safe for use on lawns, then we recommend Southern Ag Amine 2,4-D Weed Killer. While not an organic product, it kills a very wide range of weed species and is safe for most popular types of lawn grasses.

FAQ

• When should I apply weed killer?

  For the best results, you need to apply weed killer at the right times throughout the year. According to Noah James, landscaper and owner of Liberty Lawn Maintenance, when using a pre-emergent weed killer, you should apply it in the early spring once soil temperatures are regularly at 55 degrees or higher, but before weeds have actively begun to sprout. He notes that a second fall application can be needed in warmer climates where annual weeds tend to sprout over the winter.

  When using a post-emergent weed killer, however, he says, “These products shine brightest when weeds are actively growing, which means mid to late spring and early summer are prime times for application.”

  It’s not uncommon to need more than one application of any weed killer, but always check the product package for the specifics on how long to wait between applications, as well as the maximum number of applications safe to use annually.

• How much weed killer will I need?

  The amount of weed killer you’ll need largely depends on the area being treated, as well as the form of the product. For example, when treating an entire lawn for pesky weeds like dandelion or clover, you’ll need enough product—these are often granular weed killers, although there are liquid concentrates suitable for lawns as well—to achieve even and adequate coverage over the entire stretch of turf. However, if you are buying a ready-to-spray weed killer intended for targeting individual weeds or for weeding a small garden bed, a stretch of fence, or the cracks between pavers, then you won’t need nearly as much product.

  Generally, weed killers list the square footage that the entire container can treat, so if you need a lot of product to handle a large area, be sure first to measure your lawn or other garden space, and then buy enough weed killer to cover it. Note that for liquid concentrates, the product’s square foot coverage is based on the mixed amount, not on the amount of concentrate in the bottle.

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