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10 Best Weed Killers for Flower Beds in 2023 – Reviews & Top Picks

green and black lawnmoner on grass

green and black lawnmoner on grass

No one wants to waste a sunny Saturday afternoon reading reviews to find the best weed killer for their flower bed. Purchasing a weed killer and slaying weeds would be a far more effective use of the day!

However, there are a lot of different products on the market, and figuring out which one is right for you can be tough. We’ve done the research and written 10 reviews of our favorites to help you choose the right one.

After the reviews, there is a small buying guide to help clarify some of the differences you can expect in weed killers.

garden flower divider

A Quick Comparison of Our Winners (2023)

Rating Image Product Details
Best Overall
Winner
Spectracide Weed & Grass Killer Spectracide Weed & Grass Killer
  • Kills weeds and grass at the root
  • Prevents weed return for up to 5 months
  • Rain and watering proof in 10 minutes
  • Best Value
    Second place
    Roundup Weed & Grass Killer Roundup Weed & Grass Killer
  • Results within 9 hours
  • Makes garden and new lawn prep easy
  • Good for all weeds and grasses
  • Premium Choice
    Third place
    Hi-Yield Weed & Grass Killer Hi-Yield Weed & Grass Killer
  • 1 gallon of concentrate covers a large area
  • Kills everything
  • Double-surfactant formula for increased effectiveness
  • Monterey Thistledown Weed Killer Monterey Thistledown Weed Killer
  • Won’t usually kill surrounding plants when used properly
  • No grazing restrictions
  • Won’t kill grass
  • Roundup Super Concentrate Weed & Grass Killer Roundup Super Concentrate Weed & Grass Killer
  • Rainproof in 30 minutes
  • Noticeable results within 2–4 days
  • Super-concentrated formula goes a long way
  • The 10 Best Weed Killers for Flower Beds

    1. Spectracide Weed & Grass Killer – Best Overall

    Spectracide Weed & Grass Killer

    Type: Liquid concentrate
    Suitable Uses: All weeds and grasses
    Effective Time: 3 hours

    If your flower bed has some problem areas where you have undesirable grass or weeds growing, this weed and grass killer from Spectracide is our pick for the best overall weed killer. Even if you spray it right before it rains, you’ll still see it working within 3 hours, and the results typically last for up to 5 months. One jug mixes around 10 gallons of water. So, this weed killer will go a long way.

    The main downside to this weed killer’s effectiveness is that it kills almost everything! So, when spraying it, care must be taken if you have plants or flowers that you aren’t trying to kill.

    Pros
    • Kills weeds and grass at the root
    • Prevents weed return for up to 5 months
    • Rain and watering proof in 10 minutes
    • 3 hours for initial results
    • Treats approximately 3,000 square feet
    Cons
    • Kills things you may want to keep
    • Only ideal for spot treatment

    2. Roundup Weed & Grass Killer – Best Value

    Roundup Weed & Grass Killer

    Type: Liquid concentrate
    Suitable Uses: all weeds and grass
    Effective Time: 9 hours

    If you’re looking to save a few bucks but still get a quality product that does the job, this Roundup product is the best weed killer for the money. It will start to work within 9 hours and kills any grass or weeds down to their roots so they won’t regrow.

    However, it won’t prevent other weeds from regrowing in the area. So, this one will require multiple treatments if there are problem weeds that keep spreading. Also, you don’t want to use it if you’ve planted anything you plan to eat.

    Pros
    • Results within 9 hours
    • Makes garden and new lawn prep easy
    • Good for all weeds and grasses
    • Inexpensive
    • Rainproof in 30 minutes
    Cons
    • Won’t prevent future weed growth
    • Not suitable for use around fruits or vegetables

    3. Hi-Yield Weed & Grass Killer – Premium Choice

    Hi-Yield Weed & Grass Killer

    Type: Liquid concentrate
    Suitable Uses: Grass, broadleaf weeds, and woody brush
    Effective Time: Seven days

    If you’ve got a lot of space to cover, this killer from Hi-Yield is a great choice. The concentrate will mix in enough water to cover over 25,000 square feet. The manufacturer warns that this product is not for use on your lawn because it will kill everything—not just the thistles or dandelions.

    Overall, this is an excellent choice if you have a large space you’re attempting to treat. It’s a little more money upfront for the bigger jug of product, but it will go a long way since it is a super-concentrated formula.

    Pros
    • 1 gallon of concentrate covers a large area
    • Kills everything
    • Double-surfactant formula for increased effectiveness
    • Can plant in the area within one day of application
    Cons
    • Won’t prevent future weed growth
    • Expensive

    4. Monterey Thistledown Weed Killer

    Monterey Thistledown Weed Killer

    Type: Liquid concentrate
    Suitable Uses: Broadleaf weeds and thistles
    Effective Time: Up to 2 weeks

    This weed killer from Monterey is a great option if you have a thistle problem. It’s not recommended that you use this weed killer near fruit or vegetables, though, as they may be susceptible to it. For the most part, it will only target thistles and broadleaf weeds, but that’s not a guarantee. However, it’s safe for grass, so this killer will do the trick if your lawn is overrun with dandelions.

    If you’re looking for a way to clear an area of thistles before planting a flower bed, this is a great option. Sometimes it can take a while to work, but once it does, the thistle is dead as can be and won’t come back. Keep in mind that this product won’t prevent future weeds; it only kills existing ones.

    Pros
    • Won’t usually kill surrounding plants when used properly
    • No grazing restrictions
    • Won’t kill grass
    • Very effective—but can be slow
    Cons
    • Only designed for thistles and some broadleaf weeds
    • Expensive for how much you get

    5. Roundup Super Concentrate Weed & Grass Killer

    Roundup Super Concentrate Weed & Grass Killer

    Type: Liquid concentrate
    Suitable Uses: All weeds and grass
    Effective Time: 2–4 days

    Another Roundup product that makes the list is this super-concentrated formula. If you’re looking for a liquid concentrate that will go a long way, this one’s worth checking out. It’s easy to mix and will be rain or watering proof within a half hour. Plus, you can expect to see weeds dying within a couple of days.

    Other than its expensive price tag, this weed and grass killer is only for spot treatment unless you plan to replace the entire lawn because it will kill the grass. So, it won’t be ideal for every situation.

    Pros
    • Rainproof in 30 minutes
    • Noticeable results within 2–4 days
    • Super-concentrated formula goes a long way
    • Kills target at the root
    Cons
    • Expensive
    • Spot treatment only

    6. Gordon’s SpeedZone Lawn Weed Killer

    Gordon's SpeedZone Lawn Weed Killer

    Type: Liquid concentrate
    Suitable Uses: Common turfgrass weeds
    Effective Time: 2–3 days

    Your lawn should be lush and green, not dotted with yellow dandelions or other pesky weeds. This lawn weed killer is specifically formulated for use on your lawn. It will kill the weeds quickly without damaging the grass. Keep in mind that there are a few types of grass listed that it’s not safe for, so be aware of that before purchasing.

    If you live in a hot climate, you’ll want to apply this one in the early morning or late evening because hot weather encourages the killer to burn and harm grass it would otherwise be fine on. Also, certain states restrict the sale of this particular product, so check that it’s available for delivery where you live before ordering.

    Pros
    • Won’t kill the grass
    • Nearly 20,000 square feet of coverage
    • Grass can be reseeded on the treated area within 2 weeks
    Cons
    • Restricted in some states
    • Cool-weather application is better
    • Expensive

    7. Roundup Pro Weed Killer Concentrate

    Roundup Pro Weed Killer Concentrate

    Type: Liquid concentrate
    Suitable Uses: Common weeds in turfgrass
    Effective Time: Non-preventative

    This massive jug of weed and grass killer is formulated to kill everything it touches. So, it’s great if you need to prepare a field for planting or redoing multiple lawns. This is a great buy for the person who has a small to medium-sized landscaping business.

    However, for the average homeowner, this product is going to be expensive. Also, unless you’re very experienced or have some tools to help, it’s an awkward jug to mix safely without wasting any of the chemicals.

    Pros
    • Concentrate will do over 400,000 square feet
    • Kills everything effectively
    • Doesn’t contaminate the soil
    Cons
    • Expensive
    • Kills everything, including grass
    • Awkward container for mixing

    8. Green Gobbler Weed & Grass Killer

    Green Gobbler Weed & Grass Killer

    Type: Liquid spray
    Suitable Uses: weeds and grass
    Effective Time: Up to 24 hours

    If you’re looking for a natural option, this weed and grass killer from Green Gobbler is a good option. Once dried, it’s safe for humans and pets, according to the manufacturer. Its ideal use is as a spot treatment because it kills everything it touches, so make sure you’re using it on a calm day to prevent overspray.

    Another thing worth mentioning is that it can be quite harmful to things that are sensitive to its acidity. For example, if you spill some on the garage floor, it’s possible that it will eat through the concrete’s coating.

    Pros
    • Certified for organic use
    • Glyphosate-free
    Cons
    • Kills everything it touches
    • Non-concentrate so doesn’t go as far for the price
    • Not as effective as chemical killers
    • Will destroy anything sensitive to its acidity

    9. BioAdvanced Weed & Feed

    BioAdvanced Weed & Feed

    Type: Granulated
    Suitable Uses: Southern lawns
    Effective Time: Several days

    If you live in the south and you’re looking for a product that does more than one job, this 3-in-1 weed and feed by BioAdvanced is worth checking out. Not only does it kill weeds and prevent new growth for up to 6 months, but it’s also a fertilizer to keep your lawn healthy.

    Because of its formula, it’s only suitable for the types of grass that grow in warm climates. It will not work as advertised on northern lawns. Another thing to consider is that it’s not immediately safe for pets and children after application. It has to be water and allowed to dry before it’s safe to walk on.

    Pros
    • Long-term protection from weeds
    • 3-in-1 formula
    Cons
    • Formulated for southern turfs only
    • Will kill grass that it’s not designed for
    • Only enough for 5,000 square feet
    • Only suitable for warm weather application

    10. Pet-Safe Weed Killer

    Pet-Safe Weed Killer

    Type: Liquid spray
    Suitable Uses: Most common weeds
    Effective Time: 24 hours

    Pet-Safe weed killer is a reasonable option if you’ve got some furry family members around. According to the manufacturer, there are no harmful chemicals in the formula, so animals and humans are safe. Even being a natural option, it’s designed to kill everything—that can be good or bad. Ensure you’re applying it on a calm day, so it only goes on what you want to kill.

    Like any non-chemical option, there are complaints that it doesn’t work as well as some other weed killers. But that’s a small price to pay if you’d prefer not to use chemicals. Also, because of its high acidity, it can damage anything susceptible to acid damage.

    Pros
    • Natural ingredients
    • Safe for use around pets
    Cons
    • Not as effective as chemical killers
    • Will damage things that are sensitive to high acidity
    • Kills everything it touches
    • Expensive for what you get

    garden flower divider

    Buyer’s Guide: How to Select the Best Weed Killers for Flower Beds

    If you’re still undecided because you’re not sure what the different things on the various labels mean, you’re not alone. Below we’ve listed some common terms you’ll find on a weed killer’s packaging to help you decide which one is right for you.

    Types of Weed & Grass Killers

    Contact

    A contact weed killer does exactly as the name suggests. Rather than the weed’s system circulating the poison, the chemical kills whatever part of the plant it touches.

    Selective 

    A selective weed killer typically targets specific weeds or grasses. For example, the Monterey Thistledown product above specifically attacks thistles and some broadleaf weeds.

    Non-Selective 

    A standard grass and weed killer would be considered non-selective. Whatever you spray this weed killer on dies—weed, grass, vegetable, flower—it doesn’t matter.

    Residual

    A residual weed killer, also known as a pre-emergent formula, will stay in the area that you spray. This prevents future growth from new weeds after it has killed the original weed

    Systemic

    Unlike a contact weed killer, a systemic doesn’t kill the part of the plant it touches. Instead, it travels throughout the weed’s circulatory system and typically kills it at the root, which destroys the entire weed.

    photo of grass and mountain
    Image Credit: engin akyurt, Unsplash

    Choosing the Right Weed Killer

    When it comes to making sure you’re getting the right weed killer, you need to figure out what you’re trying to kill. Are you trying to kill specific weeds, or are you trying to kill everything in the area, including grass? Do you want something that will prevent new weeds from growing? These are some of the questions you’ll need to ask yourself.

    Applying the Weed Killer

    Liquid concentrates are one of the most common weed killers for homeowner use. In some cases, you apply a liquid killer directly to the plant. But most times, you’ll dilute it with a specific amount of water and put it in a sprayer. There are several sprayers available. This multi-purpose garden sprayer is an excellent option for easy mixing and application.

    garden flower divider

    Conclusion

    The Spectracide weed and grass killer is the best overall pick if you’re looking for something that’s a reasonable price, and it will kill everything at the root and prevent future weed growth for up to 5 months.

    On the other hand, if you want to save some money and aren’t so worried about preventing future growth, the Roundup concentrate is a good option.

    We hope these reviews have helped make sense of the many weed killers available for your flower bed.


    Featured Image Credit: Daniel Watson, Unsplash

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