Affiliate Disclosure:This Old House’s Reviews Team is committed to delivering honest, objective, and independent reviews on home products and services. To support this business model, This Old House may be compensated if you purchase through links on our website.
In this buying guide, our Reviews Team explores some of the best weed killers available in the market today. We’ll take a closer look at lawn weed killers, non-specific herbicides, pre-emergent weed control, and even a couple of herbicides that work well in organic gardens.
Below, we’ll go over our top picks, key features, benefits, and limitations to provide you with all the information you need to make an informed decision.
Top 6 Weed Killers
- Best Weed Killer Concentrate: Sunday Weed Warrior Herbicide Concentrate
- Best Non-Toxic Weed Killer: Green Gobbler Vinegar Weed & Grass Killer
- Best Weed Killer for Large Areas: RM43 43% Glyphosate Plus Weed Preventer
- Best Weed and Grass Killer: Spectracide Weed & Grass Killer
- Best Weed Killer for Lawns: Roundup All-in-One Weed Killer for Lawns
- Best Weed Killer for Flower Beds: Ortho GroundClear Weed & Grass Killer
Compare Top Weed Killers
| Product | Targets | OMRI Listed | Active Ingredients | Quantity |
|---|---|---|---|---|
| Sunday Weed Warrior Herbicide | Bluegrass, chickweeds, algae, sorel, lichen, and more | Yes | Ammoniated soap of fatty acids | 27 ounces |
| Green Gobbler Vinegar Weed & Grass Killer | Crabgrass, dandelions, clovers, and more | Yes | 20% ethanol vinegar | 32 ounces |
| RM43 43% Glyphosate Plus Weed Preventer | Brush, grasses, trees, vines, weeds | No | Glyphosate, imazapyr | 128 ounces (1 gal) |
| Spectracide Weed & Grass Killer | All vegetation | No | Diquat dibromide, fluazifop-p-butyl and dicamba, dimethylamine salt | 64 ounces |
| Roundup All-in-One Weed Killer for Lawns | Crabgrass, dandelions, nutsedge, and more | No | MCPA, dimethylamine salt, Quinclorac, dicamba, sulfentrazone | 170 ounces (1.33 gal) |
| Ortho GroundClear Weed & Grass Killer | All weeds and grasses | Yes | Ammonium nonanoate | 128 ounces (1 gal) |
| Product | Targets | OMRI Listed | Active Ingredients | Quantity |
Best Weed Killer Concentrate: Sunday Weed Warrior Herbicide
Sunday Weed Warrior Herbicide
- $32
Prices taken at time of publishing.
Key Features
- Features OMRI-listed herbicidal soap
- Visible results in as little as 20 minutes
- Works in flower beds, near patios, along sidewalks, in mulched areas, and more
What Customers Are Saying
Satisfied customers praise Sunday herbicides for their non-toxic, natural, and organic-compatible formulas and report great success in non-selective weed control applications. Some customers indicated that weeds grew back in place after some time had elapsed.
Best Non-Toxic Weed Killer: Green Gobbler Vinegar Weed & Grass Killer
Green Gobbler Vinegar Weed & Grass Killer
- $28.98
Prices taken at time of publishing.
Key Features
- Shows results within 24 hours
- Kills crabgrass, dandelions, clovers, and more
- Works on mulch beds, sidewalks, driveways, flower beds, and more
What Customers Are Saying
Customers who left positive reviews liked that this product was inexpensive and safe for families with children and pets. Dissatisfied customers said that it left an unpleasant smell and caused damage to wood surfaces.
Best Weed Killer for Large Areas: RM43 43% Glyphosate Plus Weed Preventer
RM43 43% Glyphosate Plus Weed Preventer
- $94.99
Prices taken at time of publishing.
Key Features
- Treats 17,297 square feet for up to a year
- Rainproof within 2 hours
- Targets areas on and around bricks, cobblestones, gravel, and pavement
What Customers Are Saying
Those who left positive reviews said that this weed killer worked well on large areas and was simple to use. However, dissatisfied customers said that it took too long to kick in or that it was as effective as cheaper, generic brands.
Best Weed and Grass Killer: Spectracide Weed & Grass Killer
Spectracide Weed & Grass Killer
- $42.99
Prices taken at time of publishing.
Key Features
- Rainproof after 15 minutes
- Visible results in as little as 3 hours
- Works on driveways, walkways, fences, trees, flower beds, shrubs, and more
What Customers Are Saying
Happy customers said that this product was long-lasting, fast-working, and persistent with tough weeds. However, other reviewers claimed that it caused damage to lawns and that it didn’t work as advertised.
Best Weed Killer for Lawns: Roundup All-in-One Lawn Weed Killer
Roundup All-in-One Lawn Weed Killer
- $35.19
Prices taken at time of publishing.
Key Features
- Available in ready-to-go sprayer bottler or as concentrate
- Rainproof in as little as 3 hours
- Kills Northern grasses
What Customers Are Saying
Those who liked this weed killer said that it was easy to spread and killed multiple types of plants with a minimal amount of spray. Dissatisfied customers didn’t like that it contained toxic ingredients.
Best Weed Killer for Flower Beds: Ortho GroundClear Weed & Grass Killer
Ortho GroundClear Weed & Grass Killer
- $22.99
Prices taken at time of publishing.
Key Features
- Rainproof within 2 hours
- Shows results in 15 minutes
- Works on hardscapes, landscape beds, and troubled vegetable gardens
What Customers Are Saying
Satisfied customers said that this weed killer worked quickly, didn’t kill wanted plants, and featured a simple-to-operate nozzle and wand. However, other customers said that it didn’t eliminate all of their weeds even after going through the entire bottle.
Buying Guide to Weed Killers
Not all weed killers work well for every surface or weed. Here are several factors to consider when determining which weed killer is best for your needs.
Types of Weed Control
Different types of weed killers are recommended for different types of plants and areas of application. Here are some common types of weed killers to look out for.
Contact Herbicides
This type of weed killer kills plants as soon as it makes contact with them. Contact weed killers don’t attack the root system, but they weaken weeds after multiple uses. This type of weed killer is effective for annual weeds that consistently reappear.
Residual Herbicides
These weed killers poison soil, killing all plants within the treated area. They can be long-lasting, so it’s best to avoid using this type of weed killer in areas that contain edible plants.
Systemic Herbicides
Systemic weed killers are applied directly to the foliage of a plant. They take several weeks to start working, but they fight the plant’s internal root system. This type of weed killer is good for plants that are difficult to kill, such as dandelions and poison ivy.
Weed Emergence
Emergence refers to how far along in the weed’s growth cycle that weed killer needs to be applied. Some weed killers are pre-emergent, meaning they should be applied to prevent weeds from growing.
Post-emergent weed killers are used for weeds that have already sprouted. They kill the plant while also ensuring it doesn’t grow back.
Selective and Non-Selective Weed Killers
If you’re using a weed killer on flower beds or gardens, it’s critical to look for selective weed killers, as they avoid beneficial plants and solely target weeds. Meanwhile, non-selective weed killers destroy all plants in the vicinity.
Frequently Asked Questions About Weed Killers
How do weed killers work?
Generally, weed killers are herbicides that interfere with weed growth by either destroying their root formation or restricting the growth and development of their cells, causing them to eventually die.
Are weed killers dangerous around pets?
It depends on the weed killer. Some aren’t safe for households with pets, while others are safe once they’re dry. The safest option is a weed killer with an organic formula.
For specific guidance on herbicides and active ingredients to look out for, visit the Environmental Protection Agency (EPA) website.
What does OMRI mean?
OMRI stands for the Organic Materials Review Institute, a non-profit organization that provides independent reviews of products intended for use in organic farming and processing. OMRI reviews the ingredients and manufacturing processes to ensure they meet organic standards, and their evaluations are used by organic certifiers to determine if products are allowed for use in organic production.
What are the best weed killers for organic gardens?
Organic gardeners may prefer natural weed killers that vinegar, citric acid, clove oil, and other use organic garden friendly ingredients instead of harsh, harmful chemicals.
However, it’s important to note that even natural weed killers can harm desirable plants if not used correctly and can be toxic if consumed, so always read and follow the instructions carefully.
What is Glyphosate?
According to the EPA, “glyphosate is a widely used herbicide that controls broadleaf weeds and grasses.” It was approved for use in United States in 1974 and undergoes re-evaluation and review by the EPA every 15 years.
How long does it take for weed killers to work?
Typical weed killers will take anywhere from two to six weeks to fully kill the root of a plant. Certain types of herbicides will produce faster results, but these herbicides kill the flowering part of the plant and not its root system.
Who This Weed Killer Guide Is For
Whether you’re a budding gardener, professional landscaper, or seasoned homeowner, an effective, safe weed killer can be key to transforming your outdoor space into an oasis.
How We Selected the Best Weed Killers
To provide our readers with the best weed killer recommendations possible, we rely on several key sources of information to help guide our selection process.
Initial Research: Our research process began by generating a list of weed killers with a significant number of verified-buyer reviews and an average customer review rating of 4–5 stars. We looked at positive and negative reviews alike, focusing on information from both satisfied and critical buyers.
Expert Insights: Through our years of experience, we’ve learned that listening to what others have to say is key to building accurate, well-rounded articles. To complement our in-house expertise, our team looked information from trusted publications and subject matter experts. We also drew insights from reader contributions.
Final Product Selection: We then pared the list down further by comparing each weed killer’s pros, cons, applications, and eliminating formulas that posed major health and safety concerns. We did of all this to find the best-in-class options for a variety of vegetation types and scenarios.
Why You Can Trust Us
This Old House has empowered homeowners and DIYers for more than four decades with top-notch home improvement advice in the form of television programs, print media, and digital content.
Our small team focuses on creating in-depth product and service review content. To date, we’ve published countless reviews of garden, lawn, and outdoor products—from fertilizer and garden hoses to patio furniture and snow blowers.
Once we conclude our research, we craft a comprehensive, user-friendly article of recommended products and additional information to help our readers make the right purchase.
Questions or Comments?
To share feedback or ask a question about this article, send a note to our Reviews team at reviews@thisoldhousereviews.com.