Weed And Seed Spray

Keep your outdoor space free from unwanted growth with a weed killer. We researched the best formulas to help you find the right one for your yard. Read on to learn how weed killers work and see why recommendations for the top weed killers. When applied correctly, the best weed killer should wipe out invasive plants completely so you can avoid re-applications.

The Best Weed Killers to Use in Your 2022 Landscape

Our top pick is the Spectracide Weed and Grass Killer Concentrate

Amanda Rose Newton holds degrees in Horticulture, Biochemistry, Entomology, and soon a PhD in STEM Education. She is a board-certified entomologist and volunteers for USAIDs Farmer to Farmer program. Currently, she is a professor of Horticulture, an Education Specialist, and pest specialist.

Barbara Gillette is a master gardener, herbalist, beekeeper, and journalist. She has 30 years of experience propagating and growing fruits, vegetables, herbs, and ornamentals.

Jennifer Klump has been a fact-checker for The Spruce since 2019. She has 22 years of experience as a librarian conducting literature searches on health, wildlife, and education. Jennifer is a technical librarian with ASRC Federal, where she fields requests related to air quality issues for the EPA.

We independently research, test, review, and recommend the best products—learn more about our process. If you buy something through our links, we may earn a commission.

The Spruce / Sabrina Jiang

Weed killers ensure that your landscape looks its best year-round, without invasive weeds, crabgrass, dandelions, or sedges. We researched numerous weed killers and evaluated each on several key features, including how easy it was to use, the length of protection it offers, and the value for the price point.

Here are our top picks for the best weed killers.

Best Overall: Spectracide Weed and Grass Killer Concentrate

Courtesy of Home Depot

Kills weeds and grasses

Rainproof after 15 minutes

Use on hardscapes

Pump sprayer recommended

Can kill unprotected grass

Spectracide is a popular choice for areas where quality results count, such as golf courses, sports stadiums, and turf grass. And its quality and strength come from its diversity. You can apply it to flower beds, around trees, and even hardscapes, such as walkways and patios. You can expect results the same day it’s applied, and it is weatherproof within 15 minutes.

Coming in a 64-ounce container, you must dilute it first and then apply it with a tank sprayer. Alternatively, Spectracide comes in a ready-to-use spray format. To achieve the best success and reduce spray drift, apply it during warm, sunny days with minimal wind.

Price at time of publish: $43

Application Type: Spray︱Targeted plants: Broad-leaf Weeds︱Rain Resistance Time: 15 minutes︱Volume: 16 ounces, 32 ounces, 40 ounces, 64 ounces, 1 gallon

According to Iowa State Extension, rain resistance is the time a herbicide needs to remain on its target before rain falls on it since water can dilute its effectiveness. Product packaging should contain this information.

Best For Lawns: Southern Ag Amine 2,4-D

Effective against many hard-to-get-rid-of weeds

Works on all grass types

Does not burn grass

Toxic, requires re-entry period

Southern Ag 2,4-D ensures that weeds do not ruin the look of your hard-earned beautiful grass. This concentrated formula targets broadleaf weeds such as clover, dandelions, and even crabgrass. It is an excellent value for the money, as all you need is a mere tablespoon per gallon of water.

Once diluted and sprayed, it kills weeds fully within three days, with visible results apparent within 30 minutes. It should be noted that 2,4-D is toxic to people and pets, so it is recommended that you not use the sprayed area for 24 hours.

Price at time of publish: $19

Application Type: Spray︱Targeted plants: Broadleaf Weeds︱Rain Resistance: None︱Volume: 32 ounces

Best Indoor: Ortho Weed B Gon Chickweed, Clover & Oxalis Killer for Lawns, 16oz.

Targets tough weeds such as dandelions

Rainproof within an hour

Advised not to use around pets

Selective herbicides, such as Ortho Weed B Gon, target weeds without harming the grass. From dandelions to clover, Ortho kills over 200 weeds at a great price point. Coming in multiple sizes, a single gallon should cover 64,000 square feet, nearly the size of a soccer field.

Since this product kills weeds at the roots, you should see results the same day; noticeable weed demise within 30 minutes has been reported. Perfect for northern and southern grass types, the formula is rainproof within an hour.

Price at time of publish: $11

Application Type: Spray︱Targeted plants: Broadleaf grasses like dandelions and clover︱Rain Resistance Time: 1 hour︱Volume: 16 ounces, 32 ounces

Best Along Fences: Gordon’s SpeedZone Lawn Weed Killer, 20 Oz.

Gordon’s Speed Zone effectively keeps weeds from growing under fence lines or creeping into lawns. A combination of 2, 4-D, dicamba acid, and carfentrazone-ethyl creates a dynamic weed killer capable of destroying over 200 species.

Gordon’s works best when you mow grass two days before or after applying the product and when rain is absent in the forecast. Unfortunately, this product is not rainproof, so it might not be recommended for locations with significant rainfall. Pets and children must avoid sprayed areas.

Price at time of publish: $41

Application Type: Spray︱Targeted plants: Broad-spectrum weeds︱Rain Resistance Time: None︱Volume: 20 ounces

Best Preventative: Preen Garden Weed Preventer + Plant Food

Can use around edibles

Contains plant food

Prevents 25+ kinds of broadleaf weeds

Does not control present weeds

Preen Garden Weed Preventer is designed to prevent weeds from popping up in your flower beds, around the base of trees, or even the vegetable garden. Its patented blend includes a plant fertilizer that helps keep your flowers blooming and vegetables growing—all while keeping weeds under control. Offering protection from nearly 30 broadleaf weeds, its granular format makes it less likely to blow onto your lawn.

The standout feature is how easily the product spreads. The bottle is designed with a convenient shaker cap: Just shake it over the intended area, add water, and you are done. Also, you needn’t worry about timing, as you can apply Preen at any point during the year. It is also safe to use around vegetables, bulbs, and over 200 other flowering plants.

Price at time of publish: $36

Application Type: Granular︱Targeted plants: Preventive against 25 broadleaf species︱Rain Resistance: None︱Volume: 7 pounds

Best Enabler: Hi-Yield Spreader Sticker

Use on all plants

Increases herbicide absorption

Works with insecticides, fungicides, and miticides

Does not control weeds on its own

Hi-Yield Spreader Sticker is a chemical enhancer, which helps improve the performance of the herbicide you are using. By increasing the herbicide’s ability to make its way into the plant tissue, it shortens the time needed to see results and increases the likelihood of success. This product is registered for use on most crops, grasses, trees, and shrubs.

You can use it as more than just a herbicide: Combine it with miticides, pesticides, and fungicides offering the same increased absorption power. Coming in at under $20 for a 16-ounce concentrate, you can get dozens of doses out of a single container.

Price at time of publish: $19

Application Type: Spray︱Targeted plants: None︱Rain Resistance: 1 hour︱Volume: 16 ounces

Best For Hot, Humid Weather: Ortho WeedClear Lawn Weed Killer

Intended for hot climates

200+ weeds controlled

Not recommended for northern grasses

Many herbicides are not meant to be applied in hot or humid weather, prevalent in the southern U.S. Ortho designed a special version of their popular Weed Clear line for the South. It is specially crafted and tested to ensure it removes weeds but shuns major grass types grown in the region.

See also  Bird Seed That Won't Sprout Weeds

Nor is rain a concern since Ortho Weed Clear is rainproof and ready to go in under an hour. It takes care of more than 200 broadleaf species, including tough-to-kill dandelions and crabgrass. The formula includes 2,4-D, so use caution in areas with heavy foot traffic.

Price at time of publish: $23

Application Type: Spray︱Targeted plants: Broad-leaf weeds including dandelions︱Rain Resistance Time: 1 hour︱Volume: 1 gallon

Best for Flower Beds: Fertilome Over The Top Grass Killer

Targeted weed control

200 + weeds controlled

Proper application is essential

Keep your flower beds looking picture-perfect with the Fertilome Over the Top Grass Killer II, which comes in a 16-ounce concentrate with a convenient hose attachment. Attach it to your hose, spray, and go! This herbicide kills tough weeds and grasses to the root, and its selective nature allows you to easily target annoying weeds without harming your flowers.

You can use this formula in and around vegetable gardens, flower beds, tree rings, and mulched beds, as well as on cracks in driveways, walkways, and patios. It is not rainproof, so it is best applied on days rain is not in the forecast. Mowing beforehand is also recommended.

Price at time of publish: $30

Application Type: Spray︱Targeted plants: Broadleaf weeds, including dandelions, Bermuda, and crabgrass︱Rain Resistance Time: None︱Volume: 16 ounces

Best Natural: Green Gobbler Organic 20% Vinegar Weed & Grass Killer

Courtesy of Amazon

Contains no harsh chemicals

Can be used in various places

No dilution needed

No smaller sizes available

Many weed killers contain harsh chemicals; however, Green Gobbler Vinegar Weed and Grass Killer is glyphosate-free and made without any synthetic ingredients. Derived from corn, it can take care of unwanted crabgrass, dandelions, clover weeds, white clover, mold, and more.

We tested this natural weed killer in a real-world going-over and successfully used it on driveways, sidewalks, concrete, mulch, and flower beds. You can expect to see visible results in less than 24 hours, and the manufacturer offers a 100 percent satisfaction guarantee. Because it is vinegar based, it is not weed-specific and can harm all grass and plants. Make sure you use it only in areas where weeds are present, not plants you want to keep.

Price at time of publish: $30

Application Type: Spray︱Targeted plants: Crabgrass, dandelions, and other listed weeds︱Rain Resistance Time: Not listed︱Volume: 1 gallon

“Once I used the weed treatment, I did not see the weeds return to my mulch beds even weeks after application. The same was true growing in the cracks on my driveway. I did pull the weeds after the Green Gobbler Vinegar Weed Killer killed the plants themselves. This was an important step to make sure that they didn’t come back.”—Katie Begley, Product Tester

The Spruce / Katie Begley

Best for Gravel: Ortho GroundClear Year Long Vegetation Killer

Can use in various places

Prevents weeds from growing back

Rainproof in an hour

Harms grass and desirable plants

Weeds popping up along walkways, the patio, or the driveway have their own challenges. You can eradicate them quickly with Ortho Ground Clear Weed Control. Unlike many formulas intended for hardscapes, it contains no harmful glyphosate. This concentrated formula comes in a 1-gallon container that makes up to 21 gallons of spray and treats more than 20,000 square feet (larger than a hockey rink). This product is ideal for locations where you want no vegetation, such as gravel paths, driveways, parking areas, fencerows, patios, and around buildings.

In addition to killing growing vegetation, it also prevents new weeds for up to a year. The formula is rainfast in one hour. You can buy it in assorted sizes, including one with a handy wand applicator, best suited for targeting hard-to-reach cracks and crevices.

Price at time of publish: $28

Application Type: Spray︱Targeted plants: All weeds, grasses, vines, brush, and trees︱Rain Resistance Time: 1 hour︱Volume: 1 gallon

Best for Large Areas: BioAdvanced Weed Killer for Lawns

Can use in various places

Prevents weeds from growing back

Rainproof in 2 hours

Not for certain plant and grass types

When you have a large area that needs to be treated for weeds, a concentrated solution can be more effective than a ready-to-use solution. Our pick for this option is BioAdvanced Weed Killer For Lawn. Covering 20,000 square feet (larger than a hockey rink), this spray features a handy hose attachment, making it easy to dilute and go.

You can use this herbicide on walkways, driveways, and beside buildings and fences to kill weeds, grasses, vines, and brush. The formula contains no glyphosate. It is rainproof two hours after application—though the manufacturer recommends applying it on a warm, sunny day, with no rainfall anticipated for 24 hours. You should see results in 2 to 4 days, as it kills the weeds down to the roots. Make sure your grass and nearby plants are on the safe list provided in the label instructions. Not for use on St. Augustine grass.

Price at time of publish: $13

Application Type: Spray︱Targeted plants: All weeds, grasses, vines, brush, and trees︱Rain Resistance Time: 2 hours︱Volume: 1 gallon

The Best Weed Killers for Your Lawn for 2022

Wondering how to choose the best weed killer for your lawn? Read on to learn how weed killers work, how to apply these products, and our recommendations for the top weed killers.

If your lawn is getting out of control with weeds, hand pulling them just isn’t going to cut it. Sure, you can tug out a few by the root, but it may be difficult and time-consuming to do that for your entire yard. That’s where weed killers come in, often the best method for lawn weed control.

There are tons of lawn weed killers on the market, so it may be difficult to choose the exact right one for your lawn. The This Old House Reviews Team has rounded up the top weed killers for 2022—and how to choose them. For extensive weed control and lawn care, we recommend considering a lawn company like TruGreen.

Identifying Weeds

Before you can choose the proper weed killer, you’ll have to determine exactly what type of weed you’re dealing with. Different weed types require different treatments—what’s effective for one may do little or no damage to another.

There are three main categories of weeds: broadleaf, grassy, and grass-like.

1. Broadleaf weeds

These weeds have broad, flat leaves, so it’s unlikely you’ll mistake them for grass. They thrive in soil that’s lacking key nutrients, and they come in different types—annual, biennial, and perennial, so different broadleaf weed varieties require different chemicals depending on their life cycle.

Examples of broadleaf weeds include dandelions, ground ivy, clover, chickweed, dollarweed, thistle, and oxalis.

2. Grassy weeds

Grassy weeds have leaves that look like grass blades, and they grow one at a time. Examples of grassy weeks include crabgrass, quackgrass, goosegrass, and foxtail.

3. Grass-like weeds

This weed type resembles grass, but its leaves are more tube-like and triangular than flat. Examples of grass-like weeks include garlic, nutsedge, and wild onion.

How Weed Killers Work

Weed killers work by using chemicals that kill the weed or prevent its growth. There are a variety of different herbicide types to treat weeds at different stages of their life cycle—or before they even sprout. Here are the main characteristics to consider when choosing your specific weed killer.

See also  Plantain Weed Seeds

Pre- or post-emergent

Pre-emergent weed killers target weed seedlings before they get a chance to sprout. If weeds have already popped up, this type won’t help. Post-emergent weed killers are designed to eradicate weeds in their active growing season. You apply post-emergent weed killers directly to the plants’ leaves.

Selective or non-selective

This aspect is critical. Selective weed killers eliminate weeds without harming beneficial plants nearby, while non-selective herbicides will damage all nearby plants, even if they’re beneficial.

Systemic or topical

Systemic weed killers attack the entire plant, including the roots. Topical herbicides, on the other hand, only kill the areas where the weed killer is applied.

Persistent or non-persistent

Persistent weed killers stay active after you apply them to prevent future weeds. Non-persistent weed killers don’t offer ongoing weed control.

How to Apply Weed Killer

Even if you select the right weed killer, applying it incorrectly can make your efforts fruitless, and the wrong application can cause complications.

Many weed killers need to be diluted with water and put in a spray bottle. The product’s label will explain precisely how much water and weed killer you’ll need to combine. Some weed killers, however, come in granular form. Solid weed killers must be applied with a spreader.

When applying weed killer, timing is everything. You don’t want to apply weed killer immediately after mowing your lawn since that could harm your tender grass. The same goes for fertilizer. In both cases, wait several days before applying weed killer.

The weather also plays a role in when to apply weed killer. Applying weed killer when it’s too hot can stress your grass, and applying it right too soon before it rains means it can wash away before it gets absorbed.

The 3 Best Weed Killers

Here are the top three best weed killers for 2022.

Compare-N-Save

This powerful, fast-acting weed killer battles the exterior part of the weeds it contacts as well as the root systems. It kills stubborn weeds very efficiently, and spraying weeds selectively will ensure your lawn stays intact.

Preen Garden Weed Preventer

This pre-emergent, selective weed killer offers residual effects, with ingredients remaining active in the soil for three months after application. Preen prevents nearly 30 broadleaf weed varieties without hurting nearby plants.

Scotts Turf Builder Weed & Feed

Scotts’ most powerful weed and feed thickens grass while crowding out weeds. It’s especially effective against dandelions and clover. The company offers a satisfaction guarantee, promising your money back if you aren’t satisfied with your results.

Top Recommended Professional Lawn Care Company: TruGreen

If you’re battling stubborn weeds or confused about what weed killer is best, it may be time to call in the experts. The This Old House Reviews Team’s top selection for lawn care, TruGreen, offers both pre and post-emergent weed control.

The specialists at TruGreen can create a custom-made plan to restore your lawn to its former health and make sure it can compete against future weeds. The lawn care company offers five annual plans with varying levels of coverage in every state except for Alaska and Hawaii.

*First application. See quote for terms and conditions.

How to Prevent Weeds

When it comes to tackling weeds, the best defense is a good offense. You should always take these steps to keep your grass hardy and robust, reducing the chances of weeds taking over.

  • Water deeply and infrequently—If you want your grass to have strong, deep roots, you need to water deeply and infrequently instead of choosing shallow, daily watering. With deep, sturdy roots, your grass can grow nice and thick and compete with weeds that may try to grow.
  • Mow high—Weeds need sunlight to grow. If you let your grass blades grow taller by setting your lawn mower to the first or second highest setting, the grass will grow tall enough to cast shade on any weed seeds, preventing them from sprouting.
  • Feed regularly—Stressed lawns are more susceptible to being crowded by weeds. Feeding regularly will keep your lawn lush and make it less hospitable to enterprising weeds.

Our Rating Methodology

To provide readers with the most objective, accurate, and detailed recommendations, the This Old House Reviews Team continually researches lawn care service companies on the market. We take the following steps to obtain up-to-date information about the industry and each company we review:

  • Analyze more than 100 customer reviews from third-party review sites, such as Yelp, the Better Business Bureau (BBB), and Google Reviews, for each company
  • Secret-shop for lawn care plans and packages to get a sense of cost, offered services, and the overall shopping experience for prospective customers
  • Speak with representatives on the phone to simulate the customer service experience from each provider
  • Update information on a regular basis to ensure the most accurate information when plans or services change with each company

We use the data from our research to build an in-depth rating system that allows us to score lawn care providers on a 100-point scale. Here are the factors in our evaluation and their designated scores:

  • Plan options (30): As one of the most important factors for homeowners shopping for a lawn care service, this one is weighted heavily based on each company’s lawn coverage. Companies that offer more options, such as irrigation, weed control, seeding, and aeration services in addition to a general plan, score higher than others.
  • Trustworthiness (30): Each company’s reputation is another significant factor for homeowners to consider before signing up for a plan. We scored providers based on their BBB score, accreditation, and offered guarantees available with each purchase.
  • Additional Benefits (20): We gave extra points to companies that provide a few additional services and benefits with their offered plans, such as organic treatments, pest control services, and a mobile app for digital communication and plan management.
  • Customer Service (10): In this rating category, we awarded points to customer-focused lawn care service providers who offer weekend availability and easy communication through phones, online chats, and online resources.
  • Availability (10): We also scored companies based on their overall availability, rewarding those that are nationally available over local companies only operating in select cities or ZIP codes.

To share feedback or ask a question about this article, send a note to our Reviews Team at [email protected].

The Best Weed Killers of 2022

Control dandelion, crabgrass, and other unwelcome garden guests with the right weed killer for your needs. Ahead, learn about the different types of weed killers and how to choose between them—and don’t miss our roundup of top-favorite picks!

By Manasa Reddigari and Tony Carrick | Updated May 9, 2022 2:19 PM

BobVila.com and its partners may earn a commission if you purchase a product through one of our links.

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.

  1. BEST CONTACT:Spectracide Weed & Grass Killer Concentrate
  2. BEST SELECTIVE:Southern Ag Amine 2,4-D Weed Killer
  3. BEST SYSTEMIC:Ortho Nutsedge Killer for Lawns
  4. BEST PRE-EMERGENT:The Andersons Barricade Granular Weed Control
  5. BEST POST-EMERGENT:Green Gobbler Vinegar Weed & Grass Killer
  6. BEST NATURAL:Doctor Kirchner Natural Weed & Grass Killer
  7. BEST FOR DANDELIONS:Ortho WeedClear Lawn Weed Killer
  8. BEST FOR CRABGRASS:Preen Lawn Crabgrass Control
See also  Weed Seed Won't Germinate

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.

Type

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.

Form

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

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.

Weed Type

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.

Longevity

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.