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Weeds spread rapidly across gardens, choking out desirable plants, sucking nutrients from the soil, and blocking the sun and air that flowers need to develop beautiful blooms.
The right weed killer for flower beds isn’t always a top brand. Some popular lawn and garden products contain chemicals that actually harm soil and pose health risks. The best weed killer for flower beds is safe, sustainable, and effective at eradicating unwanted grasses.
In this guide, we look at all of the factors shoppers will want to consider before buying these products and list our top picks for best weed killers for flower beds.
- BEST OVERALL: Espoma Organic Weed Preventer, 25 Pounds CGP25
- BEST BANG FOR THE BUCK: Harris 20% Vinegar Weed and Grass Killer
- BEST FOR PERENNIAL BEDS: Bonide Captain Jack’s Deadweed Brew Concentrate
- BEST ALL-NATURAL: Natural Armor All-Natural Weed & Grass Killer
- BEST SHAKER JUG: Preen Natural Garden Weed Preventer
- SAFEST FOR PETS: Just For Pets Pet Friendly & Pet Safe Weed Killer
- BEST CHEMICAL-FREE: Green Gobbler 20% Vinegar Weed & Grass Killer
- BEST SYNTHETIC OPTION: Preen Garden Weed Preventer
Before You Buy a Weed Killer
Commercial weed killers have a stern warning on their product labels: It’s a violation of Federal law to use this product in a manner inconsistent with its labeling. This is because many weed killers contain toxic chemicals that can harm humans, pets, and the environment if not applied correctly. Using these products in a safe, responsible manner is essential.
As with all Bob Vila solutions, conservation and sustainability are our most important focus. This is especially true when it comes to growing flowers because honey bees visit brightly colored blossoms daily. Any chemicals bees pick up are carried back to their hives, and this can destroy an entire colony. We aim to give growers the tools they need to produce bountiful blooms safely and responsibly. Shoppers will want to start with the least toxic methods of weed control and prioritize solutions that will help ensure the health and longevity of the planet.
How We Chose the Best Weed Killers for Flower Beds
We extensively researched dozens of products when selecting the picks for this lineup. While we looked at popular national brands—Preen, for example, is well respected in the gardening industry—we didn’t automatically eliminate smaller manufacturers or niche brands if their products contained ingredients that effectively reduce weeds.
We gave preference to natural and nontoxic products to promote beautiful blooms without harming soil and aquatic life or killing our precious pollinators. We feel the best way to keep flower gardens from becoming overgrown with weeds is to pluck visible grasses before they get out of control—simply scheduling in 5 minutes every other morning is often sufficient. For a pervasive problem, we recommend using the products that made this lineup as well to help reduce additional weeding.
Our Top Picks
In compiling this list, we looked for the best weed killer for flower beds that won’t kill flowers—an important detail for every gardener or landscaper. These products are environmentally safe and sustainable as well as practical and straightforward to use.
Best Overall
Espoma Organic Weed Preventer, 25 Pounds CGP25
Home gardeners and landscapers who have planted their flower beds and want to keep new weeds out may want to check out Espoma Organic Weed Preventer. Thisnonselective granular formula features corn gluten, which is often used as a natural pre-emergent herbicide. It’s also simple to use: Sprinkle over bare soil in a flower bed, then water lightly, encouraging the granules to dissolve and form a barrier.
When used in combination with decorative mulch, sprinkle the corn gluten over the soil in the flower bed before layering the mulch on top.
While this organic product is labeled and sold mainly to keep weeds from sprouting in an established lawn, it will function the same way in a flower bed by helping prevent weed seeds from sprouting. However, it won’t kill established weeds. Those must be plucked out before using this organic product.
Product Specs
- Form: Granular
- Type: Pre-emergent/preventer
- Working time: Up to 6 months
Pros
- Stops weeds before they start
- All-natural formulation
- Won’t harm desirable plants
Cons
- Won’t kill existing weeds
- Will also stop desirable seeds from sprouting
Get the Espoma Organic weed killer for flower beds at Ace Hardware or True Value.
Best Bang for the Buck
Harris 20% Vinegar Weed and Grass Killer
To banish weeds in and around flower beds in a way that’s economically—and ecologically—sound, shoppers will want to consider Harris 20% Vinegar Weed and Grass Killer. It features concentrated acetic acid (vinegar) as its active ingredient. This affordably priced weed killer comes in a 32-ounce spray bottle, allowing users to apply the product directly on the offending weeds.
This nonselective weed killer should be sprayed liberally on unwanted weeds, but don’t let overspray come into contact with desirable flowers. If necessary, consider shielding those pretty posies with plastic film during application, removing the plastic after the solution has dried.
Product Specs
- Form: Liquid; ready to use
- Type: Nonselective
- Working time: Visible wilting often occurs within hours
Pros
- Ready to apply; no mixing necessary
- Comes with attached spray trigger
- Residue degrades quickly in soil
Cons
- Overspray can harm desirable plants
- Will not keep new weeds from sprouting
Get the Harris weed killer for flower beds at The Home Depot or Harris.
Best for Perennial Beds
Bonide Captain Jack’s Deadweed Brew Concentrate
The active ingredient of Captain Jack’s Deadweed Brew Concentrate by Bonide is capric acid, a saturated fat derived from coconut and palm kernel oils that kills broadleaf and grassy weeds by drying out the foliage. Available in a quart-size package with a dedicated measuring cup, this concentrate can make up to 8 gallons of spray-on contact weed killer when mixed with water.
Captain Jack’s concentrate kills several weeds over large areas without noxious odors. It can be used against annual broadleaf weeds, perennial broadleaf weeds, annual grasses, and perennial grasses, and works in temperatures as low as 40 degrees Fahrenheit.
Product Specs
- Form: Spray
- Type: Contact
- Working time: Results within a few hours
Pros
- Plant-derived active ingredients
- Noncorrosive to metal sprayer parts
- Rapid dieback of annual and perennial weeds
- Concentrate makes up to 32 gallons of weed killer
Cons
- Requires mixing with water
Get the Bonide weed killer for flower beds on Amazon or at The Home Depot.
Best All-Natural
Natural Armor All-Natural Weed u0026 Grass Killer
Natural Armor All-Natural Weed & Grass Killer is a vinegar-based post-emergent herbicide formulated to kill any weeds that dare encroach on flower beds. The natural product is an optimal choice for edging along the borders of a flower bed to create a sharp look, but it can also be used on weeds growing in the bed itself.
Natural Armor weed killer comes in a 1-gallon jug and is ready to use—no mixing or diluting necessary. Unfortunately, a sprayer is not included; users must purchase one that connects to the jug top or use the solution in a hand sprayer or a pump-type garden sprayer. For best results, weeds should be thoroughly saturated. Keep in mind that this is a nonselective weed killer, so take care not to allow overspray to get on desirable plants.
Product Specs
- Form: Ready-to-use liquid
- Type: Nonselective
- Working time: Results (wilting) as soon as 24 hours
Pros
- No mixing or diluting necessary
- Kills a wide range of weeds
- Won’t leave toxic residue in soil
Cons
- Sprayer not included
Get the Natural Armor weed killer for flower beds at Amazon, The Home Depot, or Natural Armor.
Best Shaker Jug
Preen Natural Garden Weed Preventer
Like all Preen weed preventers, this pre-emergent product stops weed seeds from sprouting, but this one is entirely natural. It contains only corn gluten, which is known for preventing seed germination. This Preen product can be used in flower beds and around other types of plants—including fruits and vegetables.
This natural product comes in granular form and is easy to apply with a shaker lid for fuss-free, uniform application. A single application will keep weed seeds from sprouting for up to 6 weeks. It can be used on bare soil or in conjunction with mulch, such as shredded bark or pea gravel. It should only be used where plants are already established. Seeds of desirable plants will not sprout if sown in soil that’s been treated with corn gluten until the granules biodegrade to the extent that they no longer act as a barrier to seed germination.
Product Specs
- Form: Granular
- Type: Pre-emergent corn gluten
- Working time: Lasts up to 6 weeks
Pros
- Prevents weeds while feeding plants
- Easy-to-apply shaker lid
- Lasts up to 3 months
Cons
- Won’t kill existing weeds
- Stops all seeds from sprouting, not just weed seeds
Get the Preen Natural weed killer for flower beds at Amazon, Ace Hardware, The Home Depot, or Tractor Supply Co.
Safest for Pets
Just For Pets Pet Friendly u0026 Pet Safe Weed Killer
The active weed-killing ingredient in this herbicide product is acetic acid—or vinegar, as it’s commonly known—plus some essential oil and citrus to give it a pleasing smell. It’s safe for both pets and the environment, but as a nonselective weed killer, it can harm desirable plants, so apply with care.
The liquid is ready to use, with no mixing or dilution required. There’s no included sprayer, however, so users must pour the liquid into a trigger-type hand sprayer or use a pump-type garden sprayer. For the best results, saturate weeds thoroughly and allow the product to dry completely before letting pets play in the area.
Product Specs
- Form: Ready-to-use liquid
- Type: Nonselective
- Working time: None listed
Pros
- Won’t harm pets
- Doesn’t stay in the soil
- Kills weeds naturally
Cons
- Overspray can kill desirable plantings
- No sprayer included
Get the Just For Pets weed killer for flower beds on Amazon.
Best Chemical-Free
Green Gobbler 20% Vinegar Weed u0026 Grass Killer
Those looking for a powerful weed killer that doesn’t contain chemicals might want to consider Green Gobbler 20% Vinegar Weed & Grass Killer. It contains a high concentration of vinegar that stops weeds in their tracks. Best of all, it has no harmful chemicals, phosphates, or bleaches that can harm the soil or the environment.
This natural product comes in liquid form and is easy to apply with a handheld sprayer or a pump-type garden sprayer. This is a full-strength liquid—no dilution is necessary. Take care not to allow overspray to come into contact with desirable flowers, shrubs, or grass. Reapplication may be required to completely kill large weeds. Avoid using a sprinkler to water the flowers after applying Green Gobbler to keep the solution from washing off the weed’s leaves. Use drip irrigation when possible to water the flowers.
Product Specs
- Form: Granular
- Type: Post-emergent liquid
- Working time: Lasts up to 6 weeks
Pros
- Prevents weeds while feeding plants
- Full-strength liquid; no diluting
- All natural
Cons
- Overspray can kill desirable plants
Get the Green Gobbler weed killer for flower beds on Amazonor at Ace Hardware.
Best Synthetic Option
Preen Garden Weed Preventer
While Preen Garden Weed Preventer isn’t an all-natural product, it’s considered safe for use in vegetable gardens and ornamental flower beds. Its nonselective granular formula is easy to use: Sprinkle around the base of desirable plants and over bare soil in a flower bed and water lightly, allowing the granules to dissolve and form a barrier.
It can also be sprinkled over mulch, such as shredded bark or pea gravel, and it will dissolve to form a barrier that prevents weed seeds from sprouting. This product will stop desirable seeds from sprouting, too, so care should be taken on where it will be spread.
Preen’s chemical formula will work continuously for up to 3 months, after which it can be reapplied. However, this pre-emergent herbicide will not kill existing weeds if any have already taken root; use a post-emergent product or pull by hand before treating the bed with Preen.
Product Specs
- Form: Granular
- Type: Pre-emergent/preventer
- Working time: Up to 3 months
Pros
- Stops weeds before they start
- Easy-to-apply shaker-lid
- Won’t harm desirable plants
- Safe to use around edible plants
Cons
- Won’t kill existing weeds
- Will also stop desirable seeds from sprouting
- Not a natural product
Get the Preen Garden weed killer for flower beds at Amazon, The Home Depot (13-pound bag), or Lowe’s.
Or, DIY Your Own Weed Killer
Commercial weed killers are relatively new. Home growers have used natural methods of controlling unwanted weeds for many years, including:
- Borax: When mixed with water, the high alkaline content of this natural mineral will often kill weeds just by spraying the solution on the weed’s foliage. Care should be taken not to overspray on desirable flowers, as it will kill them too.
- Salt: While this is a natural herbicide, it must be used judiciously to avoid endangering flowers and other desirable plants. Mix salt with water and spray weeds, but never overspray on desirable plants.
- Vinegar: Some of the products in our lineup contain vinegar because it’s a natural weed killer. Full-strength household white vinegar can also be used. Respraying may be necessary to kill weeds completely. (Do not spray desirable flowers.)
Some of the abovementioned options can be mixed with water and sprayed on unwanted weeds to kill them. Adding a couple of drops of liquid dish soap to the mix will help keep the solution on leaves longer and give natural weed killers a chance to work.
Our Verdict
Pre-emergent Espoma Organic weed killer for flower beds keeps weeds from sprouting, while the Harris weed killer for flower beds naturally destroys existing grasses without toxic residue. Popular lawn and garden options like Roundup, Ortho, and Spectracide weren’t listed because they didn’t meet our sustainability guidelines—each contains ingredients (glyphosate, 2,4D) with harmful effects.
What to Consider When Choosing the Best Weed Killer for Flower Beds
Before pulling a popular weed killer for flower beds from a store shelf, shoppers will want to take several considerations into account. Will it damage the soil? Are the ingredients harmful to humans and animals, too? These questions should be answered ahead of making a selection. Here are a few factors that shoppers will want to consider when shopping for a weed killer for flower beds.
Selective vs. Nonselective
Weed killers come in two primary types: selective and nonselective.
- Selective: Just as it sounds, a selective weed killer targets only specific types of weeds but is designed not to kill others—or desirable plants. Read labels carefully to determine which plants a selective weed killer will affect and which ones will not be harmed.
- Nonselective: This type of herbicide is designed to kill all kinds of plants—weeds and flowers alike. It’s well suited for killing weeds in a bed before desirable flowers are planted there. It can also be used along the border of a bed to keep invasive weeds from creeping into the flower bed. Care must be taken that desired plants and flowers do not come in contact with a nonselective herbicide.
Pre-Emergent vs. Post-Emergent
This distinction refers to whether existing weeds need to be destroyed, or if the gardener hopes to prevent them from taking root in the first place.
- Pre-emergent: One of the most efficient ways of keeping flower beds weed-free is to apply a pre-emergent to the soil after the ornamental plants are established. Pre-emergents, such as those made by Preen, don’t kill weeds that are already growing. Instead, they form a barrier in the soil that prevents weed seeds from sprouting. Don’t apply a pre-emergent to soil if planning to plant flower seeds, however, as the product will also keep desirable seeds from sprouting. Pre-emergent products are often labeled as “weed preventers.”
- Post-emergent: Both selective and nonselective weed killers fall into the post-emergent category of herbicides because they’re designed to kill existing plants. Post-emergent weed killers do not keep weed seeds from sprouting
Contact vs. Systemic
Designed to kill all plants, nonselective herbicides are also classified as either contact or systemic. These terms don’t always appear on product labels, though.
- Contact: This should be sprayed directly on as much of the weed’s foliage as possible, where it works to shock the plant and kill it. Precipitation can potentially wash the herbicide off before it does its job, so anyone using this type of product should avoid doing so on rainy days.
- Systemic: A systemic weed killer is sprayed on a plant’s leaves and is absorbed by the foliage, traveling through the main stem to the roots and killing the plant. While effective at killing weeds, a potential downside is the risk of the product spreading to the roots of desirable plants, killing them, too. Shoppers will want to check the label for claims such as “kills all the way to the roots.”
Natural vs. Chemical
Chemical weed killers are generally more dangerous to humans, animals, and the environment than natural varieties. Unfortunately, chemical weed killers are often also more effective than natural types, like salt or vinegar. A natural herbicide, for example, may require two or more doses to kill weeds compared to a synthetic one that contains glyphosate, which may only require one dose.
While some gardeners will DIY their own effective natural weed killer by creating a vinegar, salt, and dish-soap solution (as mentioned above), a commercial product does offer grab-and-spray convenience.
However, no weed-killing product—even a natural one—is completely harmless because accidental overspray may kill desirable plants. Plus, some all-natural products may irritate the skin of humans sensitive to the ingredients. So while natural products are less harmful overall, it’s imperative to follow the application instructions of any herbicide carefully. The most environmentally friendly method of weed removal is a manual one.
Method of Application
Application methods will vary based on the type of weed killer selected.
- Direct spray: Available in spray bottles or refill jugs, this ready-to-use formula needs no diluting and can be applied via a trigger sprayer or a pump-type garden sprayer.
- Dilute and spray: A cost-effective option suited to treating large areas of weeds, dilute-and-spray liquids come in concentrated liquid form and are mixed with plain water in a pump-type sprayer. Diluting requires measuring and mixing as well as purchasing a pump or hand sprayer for application—perhaps this is why ready-to-use formulations are more popular.
- Spread: Available in granular form, this type of weed killer requires the use of a drop spreader or a hand applicator. Pre-emergent products often come in granular form: The user sprinkles the granules in the flower bed after the desirable plants are established, and the granules dissolve and form a barrier that keeps seeds from sprouting.
FAQs
Flower beds are at their most striking when they’re full of beautiful blooms—not weeds. Gardeners are always free to use the time-honored tradition of hand weeding, but for those who’d like a little assistance, herbicides can help. Those who are new to cultivating flowers are likely to have a few questions. Here are some answers.
Q. How do I weed-proof a flower bed?
A flower bed can’t be entirely weed-proof, but weeds can be reduced by applying a pre-emergent herbicide to the bed after desirable plants are established but before weeds sneak in.
Q. What are the benefits of using weed killers for flower beds?
Unwanted weeds compete for vital nutrients that ornamental plants need to produce large, colorful blooms. Plus, a weed-free flower bed greatly beautifies any yard.
Q. How do I get rid of grass in my flower beds?
A selective weed killer that targets just grasses is one of the best ways to stop grass invasion without harming flowers.
Q. Are weed killers safe for plants?
Only if the weed killer is a selective product designed not to harm plants. If it’s nonselective, it will kill beneficial plants as well as weeds.
Q. Are natural weed killers effective?
Yes, and they’re better for the environment. We always suggest using natural weed killers before trying any chemical products.
Q. Is weed killer safe to use if you have pets?
It varies. Natural weed killers are generally safer than chemical-based weed killers, but always check the label to be sure.
Why Trust Bob Vila
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.