By Manasa Reddigari and Tony Carrick and Mark Wolfe | Updated Mar 6, 2023 9:55 AM
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Whether they crop up on your lawn, in a flower bed, in gravel areas, or between cracks in paved pathways, weeds are the gardener’s age-old enemy. They make the yard and walkway look unkempt, and they compete with desirable plants for sunlight, water, and nutrients. Some weed species can even spread to the point of disrupting natural habitats. Weed killers can suppress the invaders and keep them from overrunning the lawn, garden, and landscape.
But banishing weeds needn’t harm the environment. Generations of chemical researchers have developed numerous powerful herbicides for home use that are highly effective, relatively cheap, and easy to apply. When used sparingly and as directed, these products can help eliminate the toughest weed problems while minimizing risk to adjacent desirable plants. Unfortunately, frequent use and improper application of chemical herbicides leads to water pollution, acute and chronic health problems, collateral damage to desirable plants, and other negative effects.
Natural and organic weed killers make the best choice for everyday lawn, garden, and landscape maintenance because the active ingredients are far less risky to human health, waterways, and wildlife. We tested the following products, and they proved to be highly effective. Along with insight on weed killers, this guide offers our top recommendations backed by our test results of these products and the reasons why we consider these some of the best weed-killer options available.
Weed killer is an easy, one-step option for removing wild, unwanted grasses, but some of these products may not provide the results required by certain users. Some weed killers have the capability of killing all plant types, making them hard to use in close-quarter gardens, vegetable gardens, or grassy areas.
Bob Vila always recommends the traditional hands-on approach, pulling pesky weeds by hand or using a weeder to ensure that the only plants affected are the ones users want gone. Later in this article, we offer a DIY alternative to store-bought weed killers.
Retailers offer a broad selection of chemical, natural, and organic weed killers, but many herbicides are linked to such unintended consequences as toxicity to nontargeted plants and animals, water pollution, and human health risks. We recommend avoiding applications of most synthetic chemicals during routine maintenance—after researching 43 popular lawn and garden herbicides, we selected and tested seven low-toxicity weed killers. We were confident that they would prove to be highly effective when used as directed and safer for regular use based on their human and environmental impacts.
We timed the application of weed killers to avoid inclement weather and tested each on a minimum of 100 square feet, according to the instructions on the labels. All liquid products were applied using a backpack sprayer, or the applicator included with the product when provided, with the spray nozzle adjusted to a coarse pattern to avoid spray drift. We inspected application areas 2, 4, 8, 18, and 24 hours after spraying and noted the patterns of dieback. Then we waited 7 days and began inspecting daily for signs of regrowth.
With each of the weed killers we tested, dieback occurred within 3 days or less of the initial treatment, with no signs of regrowth for 2 weeks or more. When regrowth of perennial or woody-stemmed weeds did occur, it was significantly diminished compared to the pretreatment appearance. Secondary applications of the same products on regrowth in each area led to similar dieback patterns along with even slower, less vigorous regrowth.
We tested a variety of highly effective weed killers with low environmental toxicity that are safe for regular yard and garden maintenance. Not all weed killers are the same. For that reason, our lineup includes both pre- and post-emergent options to stop annual pesky weeds from sprouting and to knock out tough perennial grasses throughout the landscape. Here’s how our choices performed in our tests, and why we think they are some of the best weed killers around.
Green Gobbler makes grab-and-go weed control easy with no mixing required. This quart-size trigger-spray bottle is ready to use with 20 percent vinegar and water solution. Just twist the on/spray switch and target grassy and broadleaf weeds.
We tested Green Gobbler vinegar grass and weed killer at the edges of landscape beds where creeping grasses had begun to encroach and among veggie plants within raised garden beds, and it worked within hours. The Green Gobbler’s compact package and ready-to-spray bottle were convenient, but to avoid damage from overspray, we had to hold the trigger sprayer within about 12 inches of targeted weeds, which increased stooping and bending compared to tank sprayers with long spray wands. The fine mist of this weed and grass killer coated weed foliage well but with more spray mist drift than our coarse spray wand emitted. We also had to exit the area at intervals due to the overwhelming smell.
Get the Green Gobbler weed and grass killer at Amazon (2-pack), The Home Depot, or Green Gobbler.
Banishing weeds needn’t negatively impact the environment or the pocketbook thanks to this Calyptus product. To use this cost-effective biodegradable product to defoliate and kill weeds quickly, dilute one part of this pure, highly concentrated vinegar with up to eight parts water and apply with a sprayer. The high acid content erodes leaf cells and dries out foliage within 2 to 24 hours. This weed killer is best used in mulched beds and other planted areas but is not ideal for patios, sidewalks, or driveways. Repeated contact with concrete, natural stone, mortar, and some other hardscape surfaces may cause etching.
We were extremely careful when diluting this concentrated Calyptus vinegar and recommend that all users follow suit, working outdoors for better ventilation and wearing goggles and rubber gloves to protect against eye and skin irritation. We also double-checked to ensure all of the sprayer’s interior parts were made of plastic, since this acid could damage rubber and metal. We adjusted the sprayer nozzle to a coarse pattern and applied the weed killer on herbaceous weeds in garden pathways and vacant garden beds. All of the smallest weeds died within a few hours. Established, undesirable Bermuda grass runners browned out in 5 to 6 hours, but where the grass was the thickest, only the exterior portions turned brown.
This weed killer smelled so intensely of vinegar that we had to walk away from the area during treatment several times. The strong odor remained in the yard for about 24 hours. Calyptus killed more weeds for less money than the other weed killers we tested.
Get the Calyptus weed killer at Amazon.
This gallon-size Sunday Weed Warrior is premixed and comes with its own battery-powered spray pump/wand. Its ammoniated soap formula adheres well to leaf surfaces and begins killing weeds and grass on contact. As a nonselective weed killer, it’s intended for targeted spot treatment only—overspray will damage or kill lawn grass. To use, give the jug a good shake, install the sprayer adapter into the cap, and start spraying.
We tested Sunday Weed Warrior on crabgrass, clover, plantain, and wild violet in several lawn areas as well as on crack weeds on the driveway and sidewalk. It worked faster than vinegar-based products, with noticeable dieback in less than 2 hours and thorough brownout in about 18 hours. This weed killer for lawns also penetrated and killed Bermuda grass shoots more thoroughly than the vinegar products: Near total dieback occurred after one application, whereas vinegar killed off only the surface leaves and left green blades beneath.
The battery-operated sprayer was easy to use and worked well, extracting almost every drop of liquid from the jug. Plus, a concentrated refill container is available to order directly from the manufacturer. Sunday Weed Warrior was an excellent all-around weed killer for lawns, as long as users take precautions to protect against overspray.
Get the Sunday Weed Warrior weed killer at Lowe’s, Target (32-ounce spot treatment), or Sunday (32-ounce spot treatment, 2-pack).
Selective herbicides that are safe for lawns and derived from natural ingredients are rare, but Sunday Dandelion Doom fits the bill. The active ingredient, iron HEDTA, is bad news for broadleaf weeds but safe to use on grass. This 1-gallon package is ready to spray and comes with its own battery-powered sprayer attachment. Shake well, plug in the spray adapter, and spot spray dandelions, clover, thistle, and other weeds without damaging the lawn.
We tested Dandelion Doom in an out-of-the-way lawn area that was moderately infested with clover, dandelion, wild violet, crabgrass, and a few other weeds. After marking a small test plot, we sprayed the weeds individually, without being especially careful about overspray. After 24 hours, we noticed discoloration of the dandelion, clover, and violets. After the third day, most of the broadleaf weeds appeared dead.
Unlike other weed killers that cause weeds to dry out and turn brown, this product made the leaves turn black. The lawn grass and crabgrass appeared unaffected. Because of our curiosity about iron staining, we also sprayed a few weeds in cracks on the concrete driveway. The weeds died there in about 2 days, but the concrete did not stain. Sunday Dandelion Doom is an excellent choice to keep broadleaf weeds out of lawn areas.
Get the Sunday Dandelion Doom weed killer at Lowe’s, Target (32-ounce spot treatment), or Sunday (32-ounce spot treatment, 2-pack).
The active ingredient capric acid, a saturated fat that comes from coconut and palm kernel oils, kills broadleaf and grassy weeds by drying out the foliage. It makes Captain Jack’s Deadweed Brew an effective desiccant for gravel areas prone to weeds. The concentrate comes in a quart-size package with a dedicated measuring cup. Mix it with water to make up to 8 gallons of spray-on contact weed killer.
We tested Deadweed Brew on a secondary gravel driveway that was essentially two graveled tire tracks with a ridge of green weeds down the middle. Because of the tall, dense weed cover, we prepared the site by first mowing it down with a string trimmer and removing the clippings. Then we waited 3 days for some foliage regrowth to occur before broadcasting the spray over the entire weed zone with a backpack sprayer, having set the nozzle on a coarse spray pattern.
Within 4 hours after the midmorning spray application, the weed zone had turned a pale greenish brown. By the next morning, all the weeds were completely brown. We appreciated that this concentrate was odor-free, even at full strength. Captain Jack’s concentrate kills lots of weeds over large areas without noxious odors.
Get the Bonide weed killer at Amazon, The Home Depot, Lowe’s, or Bonide.
The active ingredient in this Concern product from Woodstream—corn gluten meal—is a natural byproduct of the corn wet milling process. Instead of killing existing weeds, it prevents them from growing in the first place. Spread the granules on lawns, gardens, or landscape beds twice a year to block annual weeds like crabgrass, chickweed, henbit, annual bluegrass, and many others. As an added bonus, corn gluten meal is a significant source of nitrogen that boosts lawn and garden growth.
Testing a pre-emergent product in the middle of summer is less than ideal because summer weeds are already present. In order to give it a go, we physically removed all vegetation, roots and all, from one of our dormant but infested garden beds. We avoided weed killer sprays in order to protect the latent seeds remaining in the soil. Once the bed appeared to be nothing but clean soil, we applied the granules, watered them in, then let the soil dry out for a few days per the label instructions. Through 4 weeks of observation, we noted germination of only 27 crabgrass plants and a few other seedlings in the 150-square-foot area.
Although we are not confident in the scientific value of our little test, it seems to agree with real research performed by Iowa State University scientists. However, we recommend buyers use Woodstream’s Concern weed preventer in late winter or early fall as directed for their area on the label instructions. Also, we suggest using it immediately after purchase and not storing the product for an extended period, as the scent will attract rodents and other pests. Consistent use of this pre-emergent will eliminate most of the need for other weed killers.
Get the Woodstream Concern weed killer at Amazon or The Home Depot.
Buying the best natural weed killer on the market is a reliable option for killing weeds. But, for those of us who prefer the DIY approach, there is an at-home remedy that kills weeds and can be made with the basic essentials found in most kitchens.
Bob Vila’s favorite recipe involves mixing the following ingredients in a large bowl:
After these ingredients are combined, the mixture should be poured into a spray bottle or sprayer and then applied to the unwanted plants. For best results, this mixture should be applied on a sunny day so the heat dries out and shrivels the weeds. The combination of the weed killer and the sun will attack the root systems of the weeds and speed up the killing process.
This mixture will create a full gallon of natural weed killer that can be applied to large or small patches of weeds. The remnants can be labeled and stored in the garage or with other cleaning supplies. It should be kept away from children and pets between weed control applications.
There are other common weed killer options that use harsh chemicals like Spectracide Weed & Grass Killer Concentrate, Southern Ag Amine 2,4-D Weed Killer, and Ortho Nutsedge Killer for Lawns. Since these options include some harsh ingredients that can harm desirable plants, humans, and domestic pets, we chose to recommend products for lawn weed control that contain natural vinegar, corn gluten meal, capric acid and caprylic acid, and iron HEDTA, making them safe for homes with children and pets running around.
Weed killers are not interchangeable. Some herbicides kill on contact, while others work systemically. Some selectively kill specific types of weeds, and others kill a broad spectrum of vegetation. Be sure to consider the types of weeds that need to be controlled, where they are growing, their growth stage, and the weather conditions.
Even a well-reviewed weed killer will deliver poor results if it is applied incorrectly or if the product is not designed to solve a specific weed problem. For instance, a vegetation killer designed to eliminate and prevent driveway weeds would devastate a lawn, while a lawn weed killer would be ineffective against some of the tough weeds that grow in concrete cracks. To maximize product performance and minimize the risk of herbicide failure, factor in weed-killer type, weeds it should attack, and other properties when choosing the right commercial weed killer.
Choosing the right weed killer for the job is crucial. Here are some of the most common types of herbicides.
Natural weed killers use ingredients like vinegar, which burns weed foliage with its acidic pH, and herbicidal soaps that dry out the weeds. Natural weed killers make an excellent option for situations where a nontoxic formula is crucial, such as in a vegetable garden, children’s playground, or dog park. The ingredients in natural and organic herbicides are biodegradable, so they pose the least threat to humans and animals and do not pollute waterways.
Natural herbicides are nonselective and most effective against young, tender weed seedlings, but they may kill any other plants in close proximity. Here are some other ingredients that may be included in organic weed killers.
Weed killers typically come in either a liquid spray or granular formulation.
Emergence refers to the stage of weed growth at which weed killer is applied. Users have the option of either pre-emergent weed killers or post-emergent weed killers depending upon preference:
There are three types of weeds: annual, perennial, and biennial. Annual weeds live for a single season and then die with the arrival of winter, spreading their seeds to take root and grow the next year. Pre-emergent weed killers, which stop the seeds from germinating, are often the best solution for this type of weed.
Perennial weeds have root systems that store nutrients during cold seasons, which they use to grow in the spring. Biennial weeds have a 2-year growing season; the first year they grow and the second year they produce seeds before dying. Both perennial and biennial weeds are easier to kill in the late summer or fall, just before they go into their dormant stage. Liquid weed-killer sprays are the most effective option for perennial and biennial weeds.
Some weed killers degrade in soil within a few days to weeks. While they require more frequent reapplication to keep weeds at bay, they allow users to replant the area sooner without risking damage to new plants. This makes them a better option for use in flower or vegetable gardens that are soon to be planted as well as in places where weed preventers are less effective, like gaps between paver stones in the yard.
Longer-lasting weed killers stay in the soil and keep new weeds from growing in the application area for months or even a year after application. They’re a good option for lawns or gardens requiring lasting weed control, but they can also inhibit the germination of new plants in the area. Users should avoid applying these weed killers to areas where they plan to add new crops in the near future.
If you’re wondering if weed killer is safe to use around pets and people or what type is best for killing weeds in driveway cracks, read on for answers to these and other commonly asked questions about these herbicides.
Though it depends on the type of weeds, the best weed killer for driveways will eliminate existing plants and prevent new growth from expanding driveway cracks. For this, use of both a pre-emergent and post-emergent weed killer would be helpful.
Yes, some weed killers can be toxic to people and animals. Recent studies, however, show that even toxic weed killers can be safe around people and pets if the directions are followed closely and the product is used sparingly.
Natural weed killers are effective at killing young, tender weeds outright. Since perennial weeds have established root systems, they will likely grow back after being defoliated with a natural weed killer. One or more follow-up treatments on regrowth may be necessary to kill the toughest weeds.
The best bet for permanently killing weeds is pulling them out of the ground from the root.
Yes, vinegar can be used as a weed killer. Some commercial weed killers use concentrated vinegar as a natural alternative to synthetic chemicals.
Bob Vila has been America’s Handyman since 1979. As the host of beloved and groundbreaking TV series including “This Old House” and “Bob Vila’s Home Again,” he popularized and became synonymous with “do-it-yourself” home improvement.
Over the course of his decades-long career, Bob Vila has helped millions of people build, renovate, repair, and live better each day—a tradition that continues today with expert yet accessible home advice. The Bob Vila team distills need-to-know information into project tutorials, maintenance guides, tool 101s, and more. These home and garden experts then thoroughly research, vet, and recommend products that support homeowners, renters, DIYers, and professionals in their to-do lists.
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