Whether they crop up on your lawn, in a flower bed, or along a fence, weeds are the gardener’s age-old enemy. They make your yard unsightly and your walkway unkempt, and they compete with neighboring plants for sunlight, water, and nutrients, which can weaken your cherished plants. Weed species can even spread and disrupt natural habitats. Worst of all, weeds just seem to keep coming back no matter what you do.
Read on to learn what to look for in a weed killer and find out why the ones below are our top picks among the best weed killer options available.
- BEST CONTACT: Spectracide Weed & Grass Killer Concentrate
- BEST SELECTIVE: Southern Ag Amine 2,4-D Weed Killer
- BEST SYSTEMIC: Ortho Nutsedge Killer for Lawns
- BEST PRE-EMERGENT: The Andersons Barricade Granular Weed Control
- BEST POST-EMERGENT: Green Gobbler Vinegar Weed & Grass Killer
- BEST NATURAL: Doctor Kirchner Natural Weed & Grass Killer
- BEST FOR DANDELIONS: Ortho WeedClear Lawn Weed Killer
- BEST FOR CRABGRASS: Preen Lawn Crabgrass Control
What to Consider When Choosing the Best Weed Killer
The type of weed killer you choose will dictate where you apply it and at which growth stage to apply it. Choice also depends on the types of weeds it will kill, how it will impact nearby plants, and how long it will control weeds.
Even a well-reviewed weed killer can result in product failures (hence lingering weeds) if the product is not designed to solve your specific weed problem. 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. Ahead, learn more about five different types of herbicides.
- Contact weed killers don’t circulate within a weed’s interior after application; rather, they kill the weed by destroying the part of the plant to which you apply them, usually within hours to days. They’re commonly used on annual weeds, such as crabgrass, nettle, and chickweed, which are easier to kill than perennial plants and generally die when the foliage or stems are destroyed.
- Systemic weed killers travel within a weed after they are absorbed, usually down to the roots, destroying the entire plant from the bottom up. You can expect to wait several days to several weeks to see results, although unlike contact weed killers, systemic products generally won’t state the specific period of time it takes to kill weeds. They’re a good option for perennial weeds such as dandelion, poison ivy, or ragweed. These typically are more difficult to kill because of their deeper roots.
- Residual weed killers also often referred to as “pre-emergent” herbicides provide extended weed control by preventing weeds from germinating and growing for a period of between 3 and 12 months. While residual weed killers provide an effective barrier against new weed growth, they also prevent germination of any new seeds from favorable plants.
- Selective weed killers are meant to destroy weeds but not turfgrass or other beneficial plants in the vicinity, making them the best weed killer for lawns. This type of weed killer is a good option for eradicating, for example, dandelions or thistles on the lawn or in a flower bed.
- Nonselective weed killers eradicate weeds along with any other plants in the application area. Use them along the fence or pool or in driveway or sidewalk cracks, where you won’t put beneficial plants at risk.
Chemical vs. Natural
While chemical weed killers are by far more common, there are some natural herbicides that can also be effective at weed control. Natural weed killers include citrus oil, which causes plants to dry up and die, and vinegar, which burns leaves with its acidic pH. Natural weed killers are typically used in situations where a nontoxic formula is crucial, such as in a children’s playground or in a dog park.
Although natural herbicides can be useful, they aren’t nearly as effective as chemical herbicides, which are stronger. Unlike natural methods that aren’t selective, chemical herbicides can kill weeds while leaving other plants, such as a lawn, untouched. Many chemical herbicides have a residual effect that will control weeds for months or even years after their application. Natural herbicides, in comparison, typically only last until the next rain.
Liquid/Spray: The most effective form of weed killer, liquid weed killer comes in bottles with spray nozzles that are ready to use as well as concentrates that must be mixed before use. Some weed killers consist of spray bottles that attach to a standard garden hose for treating large areas like entire lawns. Liquid weed killers are very effective since they can even cling to weeds with small leaves.
Granular: Granular weed control is usually found with lawn-care products. The granules can be distributed with a spreader, making it easier to administer over a large area such as an entire lawn. Granules can also be mixed with dry fertilizer, creating a product that kills weeds as it fertilizes. This ability to distribute herbicide and fertilizer over large areas makes granular forms ideal weed control for lawns.
Emergence refers to the stage of weed growth at which you must apply the weed killer. Pre-emergent weed killers, sometimes labeled as “weed preventers,” target and kill the germinating (sprouting) seedlings of weeds before they emerge from the soil and become visible, so they can be the best herbicide for established lawns or walkways where you won’t seed turf or flowers.
You generally apply pre-emergent herbicides to lawns or gardens before you see signs of weeds; they will form a chemical barrier in the top layer of soil that will stop the growth of seedlings underground, in effect killing them.
Post-emergent weed killers, also known as herbicides, are used to control existing weeds that have already emerged from the soil. Apply them to the leaves and stems of visible weeds in garden beds or in driveway and sidewalk cracks; the chemicals will kill the weeds either by destroying the foliage or stems or traveling down to the roots and killing the entire root system.
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 beforehand to take root and grow the next year. Pre-emergent weed killers are often the best solution for this type of weed since they can stop the seeds from growing.
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 fall just before they go into their dormant stage. Spray weed killers are the most effective option for perennial and biennial weeds.
Persistence is a measure of how long after application a weed killer remains in the soil and provides weed control before you have to reapply it.
More temporary weed killers degrade in soil within a few days to weeks, which forces you to reapply the product often to keep weeds at bay but allows you to quickly replant other plants in the area without interrupting their growth. This makes them a better option for gardens where you intend to plant flowers or vegetables in the near future or places where weeds seldom grow, 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 where you need lasting weed control, but they can also inhibit the germination of new plants in the area, so don’t use them in areas where you plan to add new crops in the near future.
Our Top Picks
The following list takes into account the above considerations to narrow the field to some of the most effective weed killers on the market. This list includes both natural and chemical herbicides for treating weeds at pre-emergent and post-emergent stages.
Spectracide harnesses the fast-acting herbicide diquat dibromide to eliminate weeds and other vegetation on contact, which is the best weed and grass killer approach. Dilute 10 tablespoons of the liquid concentrate in a gallon of water, and apply with a tank sprayer to the foliage of weeds like dandelion, clover, and ivy. The product typically works within 24 hours, and you can reapply it after 7 days. The 16-ounce concentrate covers up to 1,500 square feet.
- Type: Liquid (concentrate)
- Suitable for: All weeds and grass
- Working Time: 3 to 24 hours
- Lasts for: 1 day
- Will kill only what it contacts
- May start killing weeds within 3 hours
- Can be reapplied after 7 days
- Rain or watering will not reduce effectiveness
- Must mix with water
- Not for weed prevention
This Southern Ag selective post-emergent herbicide targets weeds like dandelion and chickweed but does not affect plants that aren’t weeds, an approach ranking it as the best weed killer that won’t kill grass. Dilute 2 or 3 tablespoons of the liquid concentrate in 3 to 5 gallons of water and spread with a hand-pump sprayer or a hose-end sprayer.
This product is suited for use on lawns, pastures, rangelands, and along fences. It provides weed control for 6 to 12 months, depending on the application site, and the 1-quart bottle covers 21,000 to 32,000 square feet.
- Type: Liquid (concentrate)
- Suitable for: Broadleaf weed control in lawns
- Working Time: 3 days
- Lasts for: Several days
- Kills broadleaf weeds like dandelion
- Does not kill other plants
- Provides weed control for 6 months or longer
- Will not kill other types of weeds
- Must mix with water before use
To deal with the most stubborn lawn weeds, consider this sulfentrazone-based selective post-emergent herbicide. It can eliminate 50 hard-to-kill weeds like purple nutsedge and kyllinga without damaging the grass or tolerant surrounding plants.
Application of this liquid formula is made easy by the built-in hose-end sprayer: Just connect the sprayer to your hose, turn on the water, and spray the systemic herbicide directly on weeds. You can reapply the herbicide after a month, and the 32-ounce bottle covers up to 5,000 square feet.
- Type: Liquid (hose sprayer)
- Suitable for: Broadleaf and common lawn weeds
- Working Time: 1 to 2 weeks
- Lasts for: 1 day
- Kills 50 types of weeds
- Can be applied again after 30 days
- Rainproof after 2 hours
- No mixing required
- Need to use hose to apply
- Not for use over flowers, most ornamentals, vegetables
Nip baby weeds in the bud with this selective pre-emergent weed killer best suited for turfgrass and garden beds. It helps prevent more than 30 types of weeds from growing—without harming most trees, shrubs, vines, or flowers nearby, making it the best weed killer for flower beds with established plants or transplants.
Apply this granular weed killer to the soil or mulch and then water (or wait for the rain) to establish a protective soil barrier to block weed growth for 4 to 12 months. One 18-pound bag covers between 2,500 to 10,000 square feet.
- Type: Granular
- Suitable for: Pre-emergent weeds in gardens and lawns
- Working Time: 6 months
- Lasts for: 6 months
- More particles per square inch for better control
- Prevents more than 30 types of grass and weeds
- Does not harm most trees, shrubs, and flowers
- One bag can cover 2,500 to 10,000 square feet
- Does not eliminate existing weeds
- Need to mow first for better results
Sold in a 1-gallon bottle that covers 1,200 square feet, this nonselective post-emergent herbicide works to control crabgrass, dandelion, and other pesky weeds using a potent, pet-safe vinegar formula. Because it’s a nonspecific weed killer, it’s best used near fence lines, pools, and patios, or in driveway or sidewalk cracks.
To apply, fill a pump sprayer with the liquid herbicide or attach the supplied trigger sprayer, then point and spray; the fast-acting product can kill weeds within 24 hours and degrades in soil within days.
- Type: Liquid
- Suitable for: Spot treating post-emergent weeds
- Working Time: 12 to 24 hours
- Lasts for: 1 day
- Pet-safe formula
- Starts killing weeds within 24 hours
- Degrades within days
- Does not prevent weeds
- Can kill any plants in the application area
Containing ocean salt water, vinegar, and soap, Doctor Kirchner’s Natural Weed & Grass Killer tops the list of natural herbicides suitable for killing all vegetation. This nonselective herbicide comes premixed in a large 128-fluid-ounce jug and is designed for full-strength use in either a garden sprayer or spray bottle.
This liquid is well suited for mow lines or keeping invasive grasses from growing between pavers as well as in sidewalk and driveway joints. This natural weed killer works quickly—plants start wilting within hours. The liquid has a long shelf life, so it will be just as potent the following year.
- Type: Natural liquid
- Suitable for: Spot treatment of all weeds and plants
- Working Time: 12 to 24 hours
- Lasts for: 1 day
- Kills weeds quickly
- All natural ingredients safe for use around pets and children
- No mixing required
- Nonselective formula kills all plants
- More expensive than chemical weed killers
Ortho’s WeedClear herbicide liquid can kill plenty of pesky dandelions without harming the grass. This selective broadleaf weed killer targets dandelions and other broadleaf weeds such as clover, crabgrass, and chickweed. The concentrated liquid comes in a 32-ounce bottle and can treat lawns up to 5,000 square feet. The product is systemic and will travel through the weed’s leaves all the way to the roots to kill it, so it won’t regrow. It’s safe for use on most turfgrass types, including fescue, zoysia grass, ryegrass, and bluegrass.
Dilute the product with water by attaching it to the end of your garden hose. WeedClear is rainproof within 1 hour. For the best results, apply WeedClear in the spring or fall when weeds are actively growing.
- Type: Liquid (concentrate)
- Suitable for: Broadleaf weeds in lawns
- Working Time: A few hours
- Lasts for: 1 Day
- Selective herbicide is safe for use on lawns
- Hose spray attachment included
- Rainproof 1 hour after application
- Must be diluted by water through hose
- Small total coverage
If you can’t decide between pre- or post-emergent crabgrass killer, get one that can do both jobs. Preen has been manufacturing lawn and garden products for consumer yards, professional sports turf, landscape, and golf course markets since 1947.
Preen Lawn Crabgrass Control provides pre-emergent control of crabgrass as well as controlling or suppressing other broadleaf weeds for up to 4 months when applied before seeds germinate. It’s safe to use on most cool- and warm-season grasses, including St. Augustine and zoysia grass.
Unlike most pre-emergents, Preen Lawn Crabgrass Control works when applied to the lawn for up to 4 weeks after crabgrass germinates, providing post-emergent control of seedling crabgrass. Do not apply this product on a recently seeded lawn, because it will prevent grass seeds from germinating. For best results, apply in the spring or fall before weed seed germination for control of weeds in established yards.
- Type: Granules
- Suitable for: Crabgrass in lawns
- Working Time: 3 days
- Lasts for: 4 weeks
- Both a pre- and post-emergent weed killer
- Works for up to 4 weeks
- Easy to distribute over broad areas
- Must be careful when using with grass or vegetable seeds
Or, DIY Your Own Weed Killer
Before commercial weed-killing products were widely available, many had to rely on homemade remedies for getting rid of unruly weeds and other plants. The products and ingredients that worked then are still suitable for use today—and many are non-toxic, eco-friendly, and natural remedies. Among the most popular are borax, salt, and vinegar.
- Borax: A natural mineral that’s mined extensively in the Mojave Desert, borax (sodium borate) has multiple uses—one of which is the ability to kill weeds. Borax is extremely alkaline—around 9.5 on the pH scale, whole most weeds are 6-7 on the scale. Weeds sprayed with a solution of borax and water will usually die.
- Salt: Found in nearly every home, plain table salt (sodium chloride) kills weeds by changing the internal water balance in their cells. A strong saline solution can be prepared by combining salt and water and then using the solution to spray unwanted weeds. The downside to using a salt solution repeatedly is that it can remain in the soil and prevent desirable plants from growing.
- Vinegar: The vinegar sold in the salad dressing aisle is quite a bit weaker than the high-potency vinegar found in some natural weed killers, such as the Natural Armor Weed and Grass Killer pick in our lineup. However, it may be potent enough to kill some weeds if used full-strength or when combined in a 1:1 ratio and sprayed on the foliage.
- Dish soap: By itself, liquid dish soap will not kill weeds, but when a few drops are added to other homemade formulations, it acts as a surfactant to help the liquid stick to the foliage where it can be absorbed by the plant. In that sense, it enhances the effectiveness of the other ingredients.
While much depends on the weed-killing goals of each user, The Andersons weed killer is one of the best pre-emergent solutions for most yards. If weeds have already appeared, try the Green Gobbler weed killer, which is our pick for best post-emergent weed killer.
How We Chose the Best Weed Killers
These recommendations for the best weed killer include a variety of products to meet the weed-killing needs of typical users who want to maintain a residential landscape. We narrowed our research to focus primarily on liquid weed killers, as those are some of the most popular on the market due to their ease of use. However, we found that one granular weed killer ranked highest in the pre-emergent category.
We also evaluated the weed killers based on how long each product stays in the ground and whether it has pre-emergent or post-emergent action, is selective or nonselective, and works on contact or systemically. While there are broad weed killers ranked on our list that can work quickly and have long-lasting effects, others are designed for killing either a targeted weed type or for targeted placement with little effect on the surrounding landscaping.
If you’re wondering if weed killer is safe to use around pets and people or what type is best for killing those weeds in the cracks of your driveway, then read on for answers to these and other commonly asked questions about these herbicides.
Q: What’s the best weed killer for driveways?
Though it depends on the type of weeds growing in the driveway, the best weed killer is one that eliminates any plants that have grown and prevents new growth from creating or expanding any unwanted cracks. For this, both a pre-emergent and post-emergent would be helpful.
Q: Are weed killers toxic to people and animals?
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.
Q: Are natural weed killers effective?
Natural weed killers are effective at burning back the tops of plants, which can help to kill off annual weeds. However, since perennial weeds have established root systems, they will likely grow back after being treated with a natural weed killer.
Q: What kills weeds permanently?
The best bet for permanently killing weeds is pulling them out of the ground from the root.
Q: Can I use vinegar as a weed killer?
Yes, vinegar can be used as a weed killer. Some commercial weed killers use concentrated vinegar as a natural alternative to synthetic chemicals.