Photo: acehardware.com
Pulling weeds is a lot of fun, said no one, ever. But if neglected, weeds can spread rapidly, choking out desirable plants, sucking vital nutrients from the soil, and blocking the sun and air flowers need to develop beautiful blooms. While many types of herbicides line garden center shelves, finding the right weed killer for flower beds needn’t be confusing.
Rather than buying a product at random and hoping it wallops weeds—without destroying desirable plants in the process—take a few minutes to check out this weed-killer guide. Learn what to consider when shopping for the best weed killer for flower beds, and find out why the following products are among the top options for keeping flower beds weed-free.
- BEST OVERALL: Preen 2464110 Garden Weed Preventer
- BEST BANG FOR THE BUCK: Harris Vinegar Weed and Grass Killer Organic
- BEST SELECTIVE FORMULA: Ortho Grass B Gon Weed and Grass Killer
- BEST EXTENDED CONTROL: Preen 246422 Extended Control Weed Preventer
- BEST ALL-NATURAL: Natural Armor Weed and Grass Killer All-Natural
- BEST WITH FERTILIZER: Preen 2164116 Plant Food Garden Weed Preventer
- SAFEST FOR PETS: Just for Pets Pet Friendly & Pet Safe Weed Killer
Photo: amazon.com
What to Consider When Choosing the Best Weed Killer for Flower Beds
Anyone who reads the fine print on labels will find that commercial weed killers come with a rather stern warning: 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/or the environment if not applied correctly. Using these products in a safe, responsible manner is essential. Consider the following when shopping for a weed killer.
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 the plants you want 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.
- 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.
- 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 the soil if you plan to plant flower seeds, however, as the product will also keep desirable seeds from sprouting. Pre-emergent products are often labeled as “weed preventers.”
Contact vs. Systemic
Nonselective herbicides—the ones designed to kill all plants—are also classified as either contact or systemic. However, these terms don’t always appear on product labels.
- Contact: This type of weed killer must be sprayed directly on as much of the weed’s foliage as possible, where it works to shock the plant and kill it. Often, the product will recommend not applying the product when rain is in the forecast because precipitation could potentially wash the herbicide off before it does its job.
- Systemic: A systemic weed killer is applied by spraying the plant’s leaves–it’s absorbed by the foliage and then travels through the main stem to the roots, where it kills the plant. This is an effective way of killing weeds, but a potential downside is the risk of the product traveling from the roots of the weed to nearby roots of desirable plants and killing them as well. While the term “systemic” may not appear on the label, look for claims such as “kills all the way to the roots.”
Natural vs. Chemical
In general, chemical weed killers are more dangerous to humans, animals, and the environment than natural weed killers. Unfortunately, chemical weed killers are often more effective than natural versions, such as products that contain salt or vinegar. For example, it’s usually necessary to apply a single dose of chemical herbicide that contains glyphosate, while users may need to apply a natural herbicide two or more times to kill the weeds, depending on the strength of the product.
While some gardeners will DIY their own effective natural weed killer by creating a vinegar, salt, and dish soap solution, 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.
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, and 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.
Our Top Picks
It was quite a quest to find the best weed killer for flower beds that won’t kill flowers! The products described here all contain ingredients known for killing weeds or for keeping weed seeds from sprouting. They’re effective and relatively straightforward to use. Still, weed-killing needs vary from gardener to gardener, so we’ve included a variety of herbicide types, both organic and chemical, including post- and pre-emergent products. Each is a standout in its category.
Photo: amazon.com
Home gardeners and landscapers who’ve already planted their flower beds and want to keep new weeds out should check out Preen Garden Weed Preventer. The nonselective granular formula is simple to use: Sprinkle around the base of desirable plants and over bare soil in a flower bed, then water lightly, which encourages the granules to dissolve and form a barrier.
Users can also sprinkle Preen over mulch, such as shredded bark or pea gravel, and it will dissolve to form a barrier that prevents weed seeds from sprouting. Be aware it will also stop desirable seeds from sprouting, so don’t apply it if you plan to sow flower seeds.
Preen comes in a jug with a shaker-type applicator top so there’s no additional spreader to purchase. The 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
Cons
- Won’t kill existing weeds
- Will also stop desirable seeds from sprouting
Get the Preen 2464110 weed killer for flower beds at Amazon, The Home Depot, or Lowe’s.
Photo: amazon.com
To banish weeds in and around flower beds in a way that’s economically—and ecologically— sound, consider Harris Vinegar Weed and Grass Killer. It features concentrated acetic acid (vinegar) as its active ingredient. This affordably priced weed killer comes in a 1-gallon jug and includes a spray trigger on a hose that connects to the jug for applying the product directly to 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 to protect them, removing the plastic after the solution has dried.
Product Specs
- Form: Liquid, ready-to-use
- Type: Nonselective
- Working time: Visible wilting often within hours (manufacturer claims “often seen immediately” but that’s a stretch!)
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 on Amazon or at Tractor Supply Co.
Photo: acehardware.com
Any gardener concerned about overspray inadvertently harming prized flowers might wish to use Ortho Grass B Gon Weed and Grass Killer. This selective chemical weed killer specifically targets invasive grasses, including crabgrass, sandbur, bentgrass, and more—without harming ornamentals.
Many types of grass can be vanquished with a single application of post-emergent, Ortho Grass B Gon, but hard-to-kill weedy species, such crabgrass and Bermuda grass, may require a second application 7 days after the first. The product comes in a bottle with an attached trigger sprayer, and no dilution or mixing is necessary. Take care not to let overspray get on lawns, where it will likely kill the grass.
Product Specs
- Form: Ready-to-use spray
- Type: Selective, kills grasses
- Working time: Not specified
Pros
- Ready to use, no mixing
- Sprayer included
- Kills grassy weeds, not ornamental plants
Cons
- Overspray can kill lawn grass
Get the Ortho weed killer for flower beds at Ace Hardware or The Home Depot.
Photo: amazon.com
Short on flower-tending time? Consider using a long-lasting product, such as Preen Extended Control Weed Preventer, that stops new weed seeds from sprouting for up to 6 months. This pre-emergent herbicide works by forming a chemical barrier at the soil level that prevents seeds from germinating.
Inside the container of this granular herbicide, users will find an applicator scoop featuring dozens of tiny holes that help disperse the product uniformly. The product can be used on bare soil or in conjunction with mulch, such as shredded bark or rubber chips. Apply only around established flowers and nonedible ornamentals. This specific Preen product is not intended for use around fruit and vegetable plants.
Product Specs
- Form: Granular
- Type: Pre-emergent/preventer
- Working time: Up to 6 months
Pros
- Applicator scoop included
- Lasts up to 6 months
- Won’t kill established plants
Cons
- Not intended for use in vegetable gardens
- Won’t kill existing weeds
Get the Preen 246244 weed killer for flower beds on Amazon or at Lowe’s.
Photo: amazon.com
Natural Armor Weed and Grass Killer is a nonselective, 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 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
Get the Natural Armor weed killer for flower beds on Amazon or at The Home Depot.
Photo: amazon.com
Like all Preen weed preventers, this pre-emergent product stops weed seeds from sprouting, but this one also provides a well-balanced dose of fertilizer to help plants grow well and develop a healthy root structure. Preen Plant Food Garden Weed Preventer contains nitrogen, phosphate, potash, and sulfur to boost plant health.
This nonselective chemical product comes in granular form and is easy to apply with a shaker lid for fuss-free, uniform application. A single application will feed plants and keep weed seeds from sprouting for up to 3 months. 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 a pre-emergent.
Product Specs
- Form: Granular
- Type: Pre-emergent (plus fertilizer)
- Working time: Lasts up to 3 months
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 2164116 on Amazon or at The Home Depot.
Photo: amazon.com
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.
Our Verdict
All of the weed killers in this lineup are among the top options for killing existing weeds in flower beds or for keeping new ones from growing, but our best overall pick, Preen Garden Weed Preventer truly stands out. It’s a pre-emergent that keeps weed seeds from sprouting, and it protects flower beds for up to 3 months. Our budget pick, Harris Vinegar Weed and Grass Killer, is an all-natural product that destroys existing weeds yet won’t leave toxic residue in the soil.
How We Chose the Best Weed Killers for Flower Beds
We extensively researched dozens of herbicides when selecting the best weed killers for this lineup. While we took popular brands into consideration—Preen and Ortho are nationally known manufacturers of quality gardening products—we didn’t automatically eliminate products from smaller or niche manufacturers if they contained the ingredients necessary for killing weeds.
We chose a variety of both selective and nonselective herbicides, as well as several pre-emergent products to satisfy the needs of different gardeners—there’s simply no one-size-fits-all product that’s suitable for all flower beds. We didn’t exclude all chemical weed killers but we gave preference to natural and less toxic synthetic products.
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.
Q. How do I weed-proof a flower bed?
You can’t completely weed-proof a flower bed. However, you can greatly reduce the number of weeds by applying a pre-emergent herbicide to the bed once 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 weedy flower bed simply looks sloppy.
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 your 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. In some cases, however, they may not be as strong as chemical weed killers, and users may need to use more than one application.
Q. Is weed killer safe to use if you have pets?
It varies. Follow the application instructions carefully. Many weed killers list a certain amount of time that must elapse before allowing pets to play in a treated area. In general, natural weed killers are safer than chemical-based weed killers.
