How do you kill weeds in your flower beds? Many homeowners turn to weed control products like pre-emergent and post-emergent herbicides. Which ones are the best to use on your flowers? Here are our top picks for the best weed killers for flower beds, divided into pre-emergents (which prevent weeds from growing in the first place) and post-emergents (which kill existing weeds).
If you’re looking to kill weeds on your lawn, in your vegetable garden, between cracks in your driveway, or elsewhere in your landscape, see our reviews of the best weed killers of the year that can work for these areas, too, and not just in flower beds.
Our top picks
Top pre-emergent weed killers for flower beds – Reviews
Pre-emergent herbicides are the products to go for if you would rather prevent weeds from popping up in the first place. They keep weed seeds from germinating, so you have to apply them long before the weeds start to poke out of the soil.
If you don’t see what you’re looking for here, you can find more options in our list of the best pre-emergent herbicides.
1. Preen Natural Garden Weed Preventer
Preen Natural Garden Weed Preventer is a pre-emergent herbicide that’s geared toward ornamentals like flowers, trees, and shrubs. It can also be used on vegetables and other edible plants.
Preventing weeds for 4 to 6 weeks, this herbicide is made with one of the only natural pre-emergent ingredients: corn gluten meal. Corn gluten meal is safe for pets and children; they can even play in your yard straight after you use it.
This product prevents all seeds from growing; it won’t kill any existing plants, which is great for your flowers, but not if you’re already dealing with weeds. This also means you shouldn’t use the product if you’re trying to grow flowers and other plants from seed.
Product details
- Active ingredients: Corn gluten meal
- Package size: 5 lbs, 25 lbs
- Selective: No
- Emergence: Pre-emergent, up to 4-6 weeks effectiveness
- Required equipment: None
- Price range: Moderate
Pros and cons
| What we liked | What we didn’t like |
| ✓ Made with natural ingredients ✓ Prevents weeds from growing ✓ Ready to use and comes with its own applicator ✓ Doesn’t mind the rain ✓ Children and pets can play in treated areas immediately after use | ✗ Won’t kill existing weeds ✗ Can’t be applied on newly-planted flower beds ✗ Must be reapplied every 4-6 weeks |
Where to buy
2. Preen Garden Weed Preventer
If you’re willing to sacrifice natural ingredients for a longer period of weed prevention, then you should consider Preen Garden Weed Preventer. Unlike its natural counterpart, this pre-emergent herbicide stops weed growth for up to 3 months.
Do you have weeds elsewhere in your yard? You can use Preen Garden Weed Preventer around 200 types of flowers, vegetables, trees, and shrubs. The only places you can’t use it are on your lawn and newly-planted landscape beds.
Product details
- Active ingredients: Trifluralin
- Package size: 5.625 lbs, 16 lbs
- Selective: No
- Emergence: Pre-emergent, up to 3 months effectiveness
- Required equipment: None
- Price range: Relatively affordable
Pros and cons
| What we liked | What we didn’t like |
| ✓ Prevents weeds from growing for up to 3 months ✓ Ready to use and comes with its own applicator ✓ Doesn’t mind the rain ✓ Relatively affordable | ✗ Won’t kill existing weeds ✗ Can’t be applied on newly-planted flower beds |
Where to buy
3. Miracle-Gro Shake ‘N Feed Weed Preventer
Homeowners that want to be as efficient as possible may choose to go for a weed and feed product like Miracle-Gro Shake ‘N Feed Weed Preventer to get both weed control and fertilization done in one day. The pre-emergent component of this product prevents weeds from sprouting for up to 3 months.
The fertilizer component is a balanced, complete fertilizer with a 10-10-10 ratio of nitrogen, phosphorus, and potassium. These three are some of the essential nutrients that plants – like flowers – need to grow.
While this product tackles both weed control and fertilization, you have to make sure that you apply it early enough in the growing season in order actually to prevent weeds. Since it’s a pre-emergent product, it can’t kill existing weeds.
Product details
- Active ingredients: Trifluralin
- Fertilizer ratio: 10-10-10
- Package size: 4.5 lbs
- Selective: No
- Emergence: Pre-emergent
- Required equipment: None
- Price range: Moderate
Pros and cons
| What we liked | What we didn’t like |
| ✓ Prevents weeds from growing for up to 3 months ✓ Feeds plants ✓ Ready to use and comes with its own applicator | ✗ Won’t kill existing weeds ✗ Can’t be used on newly-planted flower beds |
Where to buy
4. Preen Garden Weed Preventer + Plant Food
Preen Garden Weed Preventer + Plant Food is another product perfect for tackling weed control and fertilization at the same time. This weed and feed product can be used not just on your flowers but also on your other established ornamentals and edibles like trees, shrubs, and vegetables.
Unlike the other weed and feed product on our list, Preen Garden Weed Preventer + Plant Food has a nitrogen, phosphorus, and potassium ratio of 9-12-9. The increased phosphorus level can help promote more flowers on your plants.
While you can use this product throughout the growing season, it’s best to apply it early on to prevent weeds from sprouting in your landscape beds. This will give you protection from weeds for up to 3 months.
Product details
- Active ingredients: Trifluralin
- Package size: 5.625 lbs, 13 lbs, 16 lbs, 31.5 lbs
- Fertilizer ratio: 9-12-9
- Selective: No
- Emergence: Pre-emergent
- Required equipment: None
- Price range: Moderate
Pros and cons
| What we liked | What we didn’t like |
| ✓ Ready to use and comes with its own applicator ✓ Prevents weeds from growing for up to 3 months ✓ Feeds plants | ✗ Won’t kill existing weeds ✗ Can’t be used on newly-planted flower beds |
Where to buy
5. Preen Extended Control Weed Preventer
Do you want a product that gives you an even longer window of protection against weeds? Preen Extended Control Weed Preventer is the product for you. It controls weed growth for up to a whopping 6 months.
Unlike the other pre-emergent weed killers in this list, this product can be used safely around a lot more plants – more than 600 perennials, groundcovers, shrubs, and trees. As always, you can’t use this product in areas with newly-planted seeds.
Product details
- Active ingredients: Trifluralin; Isoxaben
- Package size: 4.93 lbs, 13.75 lbs, 21.45 lbs
- Selective: No
- Emergence: Pre-emergent
- Required equipment: None
- Price range: Moderate
Pros and cons
| What we liked | What we didn’t like |
| ✓ Ready to use and comes with its own applicator ✓ Prevents weeds from growing for up to 6 months | ✗ Won’t kill existing weeds ✗ Can’t be used on newly-planted flower beds |
Where to buy
Top post-emergent weed killers for flower beds – Reviews
If you already have weeds, a pre-emergent product can’t help you; you’ll need a post-emergent herbicide to solve your problems. Post-emergent herbicides attack and kill existing weeds in your flower beds.
If none of the products below seem perfect for your needs, check out our list of the best post-emergent herbicides for even more great options.
1. Just For Pets Pet Friendly & Pet Safe Weed Killer
If you have pets or young children, you’ll want an effective weed killer that’s safe for your loved ones. That’s where Just For Pets Pet Friendly & Pet Safe Weed Killer comes in.
True to its name, this weed killer gets rid of broadleaf weeds and grasses down to the root with ingredients that are less harsh than those in traditional herbicides. Its active ingredient is vinegar, which is natural but also non-selective. You should avoid overspray from getting on desired plants as much as possible if you use this product.
This product is best used when it’s warm and sunny out, but it can handle a light shower after it’s dried.
Product details
- Active ingredients: Vinegar
- Package size: 1 gal, 2.5 gal
- Selective: None
- Emergence: Post-emergent
- Required equipment: None
- Price range: Moderate
Pros and cons
| What we liked | What we didn’t like |
| ✓ Made with natural ingredients ✓ A portion of each sale is donated to animal shelters ✓ Ready to use and comes with its own applicator ✓ Starts showing results in hours ✓ Safe for pets and children ✓ Kills to the root | ✗ The nozzle that comes with the product is sometimes defective ✗ It has a strong odor that can linger for a while |
Where to buy
2. Ortho GroundClear Super Weed and Grass Killer
Crabgrass, oxalis, dandelions, and nutsedge are some of the 175 tough-to-control broadleaf and grassy weeds that Ortho GroundClear Super Weed and Grass Killer targets. These tough weeds are notoriously tricky to get rid of, especially when they’re near plants that you want to keep, like your flowers.
Weeds will start to die in hours, fully dying within 1 to 2 weeks as the herbicide makes its way down to the root system. Even though it takes hours to start seeing visible results, this product is rainproof within 15 minutes, so there’s no need to worry if rain clouds start brewing.
Although you can use this on your flower beds and other ornamental plants, you need to protect them, as this product can injure or kill them, too.
Product details
- Active ingredients: Diquat dibromide; Fluazifop-P-Butyl; and Dicamba, Dimethylamine salt
- Package size: 1 gal
- Selective: No
- Emergence: Post-emergent
- Required equipment: None
- Price range: Moderate
Pros and cons
| What we liked | What we didn’t like |
| ✓ Ready to use and comes with its own applicator ✓ Kills to the root ✓ Rainfast in 15 minutes ✓ Targets tough weeds | ✗ Flowers need to be protected ✗ Some users report that the product was shipped without the trigger ✗ The wand may fail sometimes |
Where to buy
3. Natural Armor All-Natural Weed & Grass Killer Concentrate
Targeting 250 types of weeds and grasses, Natural Armor All-Natural Weed & Grass Killer Concentrate is another natural weed killer. Although it includes concentrate in its name, it’s a ready-to-spray post-emergent herbicide. It’s safe to use around flower beds, shrubs, and other parts of your garden as long as you protect your plants from overspray.
Its active ingredient is vinegar, which is quite effective but has a strong odor. The smell can linger for a few days, so don’t apply this if you’re hosting a gathering soon after.
Product details
- Active ingredients: Vinegar
- Package size: 1 gal, 2.5 gal
- Selective: No
- Emergence: Post-emergent
- Required equipment: None
- Price range: Moderate
Pros and cons
| What we liked | What we didn’t like |
| ✓ Made with natural ingredients ✓ Ready to use and comes with its own applicator ✓ Safe for children and pets ✓ Shows results within the day | ✗ It has an odor that lingers for a few days ✗ Flowers need to be protected ✗ Sprayer sometimes fails to work |
Where to buy
4. Ortho GroundClear Weed & Grass Killer
Unlike most of the other herbicides on this list, Ortho GroundClear Weed & Grass Killer is listed as safe for organic gardening by the Organic Materials Review Institute (OMRI). OMRI is an independent organization that determines which products are all right to use in organic gardening operations.
This post-emergent herbicide starts drying out anything it touches in 15 minutes. Make sure to wash it out if any overspray manages to get on your flowers and other desirable plants as soon as possible, as it becomes rainproof in 2 hours.
Unfortunately, this weed killer doesn’t kill to the roots. You’ll have to dig up the whole weed and as much of its roots to ensure they don’t come back.
Product details
- Active ingredients: Ammonium Nonanoate
- Package size: 1 gal
- Selective: No
- Emergence: Post-emergent
- Required equipment: None
- Price range: Relatively affordable
Pros and cons
| What we liked | What we didn’t like |
| ✓ Ready to use and comes with its own applicator ✓ Starts showing results within 15 minutes ✓ Affordable ✓ OMRI-listed for organic gardening | ✗ Flowers need to be protected ✗ Dead plants still need to be picked up as it doesn’t kill the roots ✗ The sprayer fails sometimes |
Where to buy
5. Avenger Organic Weed Killer Herbicide Spray
Although it’s not OMRI-listed, Avenger Organic Weed Killer Herbicide Spray does have other certifications that recognize it as an organic herbicide. It’s registered by the Environmental Protection Agency (EPA) and approved by the U.S. Department of Agriculture’s (USDA) National Organic Program (NOP) as fit for organic gardening.
Unlike the other natural weed killers on this list, Avenger Organic Weed Killer Herbicide Spray is powered by citrus oil (d-Limonene), giving it a fresh citrus scent. The citrus oil strips away the waxy protective layer of any plants it makes contact with, causing them to dehydrate and eventually die.
Product details
- Active ingredients: D-limonene (citrus oil)
- Package size: 24 oz spray bottle; 32 oz, 128 oz/1 gal, and 2.5 gal concentrate
- Selective: No
- Emergence: Post-emergent
- Required equipment: Pump sprayer if using the concentrated version
- Price range: Moderate
Pros and cons
| What we liked | What we didn’t like |
| ✓ EPA-registered and approved by the USDA NOP for organic gardening ✓ Starts showing results within 2 hours ✓ Has a citrus aroma ✓ Ready to use and comes with its own applicator | ✗ Sprayer sometimes doesn’t work ✗ Flowers need to be protected ✗ Needs sunny weather for best results ✗ Tough weeds may need two applications to die |
Where to buy
6. Harris 20% Vinegar Weed and Grass Killer
Last on our list of the best weed killers for flower beds is Harris 20% Vinegar Weed and Grass Killer. Like other vinegar-based herbicides, it will injure any plant that it touches. This product comes in a smaller 32 oz container, which is a good size for homeowners that only need to spot-treat their flower beds.
Harris 20% Vinegar Weed and Grass Killer will cause visible burns on weeds within the day. However, it will also burn your desirable plants if you don’t protect them. It’s best to apply this herbicide when it’s expected to stay sunny for the next few days.
Product details
- Active ingredients: Vinegar
- Package size: 32 oz, 128 oz
- Selective: No
- Emergence: Post-emergent
- Required equipment: None
- Price range: Moderate
Pros and cons
| What we liked | What we didn’t like |
| ✓ Ready to use and comes with its own applicator ✓ Made with organic ingredients ✓ Shows results within the day | ✗ Has a strong vinegar smell ✗ Doesn’t kill to the root ✗ Flowers need to be protected |
Where to buy
Buyer’s guide to weed killers for flower beds
What should homeowners look for when shopping for a weed-killing product for their flower beds? Here are a few factors that you should keep in mind.
Emergence
There are two types of weed killers that differ based on when they target weeds. If you already have weeds, you should go for post-emergent herbicides, as their primary purpose is targeting existing weeds. Some post-emergent products also prevent weeds from growing for a period of time, but they’re the exception rather than the rule.
Homeowners that want to stop weeds before they sprout should consider a pre-emergent herbicide instead. They won’t do anything to existing weeds, but they’ll prevent weed seeds from germinating.
Using a pre-emergent herbicide can be a bit different than using a post-emergent weed killer. Here’s a short video from Preen that shows how their pre-emergent product works. You can use these same instructions for most granule-type pre-emergent herbicides:
Ingredients
The active ingredients in traditional herbicides are often harsh chemicals, some of which can have negative effects on your health and the environment. If you’d rather minimize the risk of harm when eradicating weeds, you could opt for natural and organic weed killers.
Some ingredients used in organic and natural weed killers are vinegar, citrus oil, and herbicidal soap. However, while they’re less harsh, you should still be careful when using natural or organic herbicides to be safe.
Root killer
Many common weeds, like dandelions, can regrow from their roots; some can even regrow from small root fragments. If you don’t want to dig around trying to get all of a weed’s roots, you should consider buying a weed killer that kills to the roots.
Ease of use
Do you want to apply and go, or would you rather be cost-effective? Going with concentrated herbicides can save you money – especially if you’re treating a large area – but they have to be diluted before use. Premixed herbicides, on the other hand, are great for homeowners that just want to get it over with as quickly and easily as possible.
Rain tolerance
Does it rain a lot where you live? If you’re planning to spray some weeds, you should know that you should have clear skies for a few days for the best results. However, some weed killers can handle a bit of water and become rainfast after a time; if you live somewhere with a lot of rain, grab an herbicide that becomes rainproof fast.
Speed
Some homeowners need the weeds in their garden gone ASAP, so the speed at which a weed killer gets its job done can be important. Those that need to replant flowers and other ornamentals soon afterward should also check how fast the weed killer dissipates, or else their new plants can get injured, too.
FAQ about weed killers for flower beds
RoundUp is a very effective non-selective weed killer, but there aren’t any RoundUp products included in this list for two reasons:
● Its active ingredient is glyphosate, which is harmful to the environment and possibly to human health as well; and
● There have been reports stating that Bayer, RoundUp’s manufacturer, plans to pull the product from the residential market in 2023.
If you don’t want to use pre-emergent herbicides to prevent weeds, you can turn to non-toxic methods. Some of these methods include:
● Hand-weeding
● Mulching
● Landscape fabric
You can read our article to find out more about natural weed control methods.
Some ingredients used to make homemade weed killer are vinegar, salt, and liquid dish soap.
If you want an even simpler DIY weed killer, you can simply boil some water and pour it over your weeds. This isn’t recommended for areas where the target weeds and desirable plants are near each other, though, as the boiling water will kill all plants in its path.
When to call for professional weed control
To keep your curb appeal up, you should take care of all aspects of your landscaping, including your flower beds. Part of flower bed maintenance is ensuring your blooms have no competitors by getting rid of pesky weeds. But what if you don’t have any time to dedicate to this important task?
If that sounds like you, consider hiring a professional lawn care service to take care of weed control and fertilization. Lawn Love can connect you with knowledgeable pros with the right tools that can help you achieve a weed-free landscape. Contact a weed control pro near you today.
Main Photo Credit: Daria Nipot | Canva Pro | License, with text overlay using Canva Pro
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