Flower beds bring color and joy to your garden but taking care of them requires care, patience, and know-how. When it comes to chemical weed management, you risk losing all the hard work and effort you put into making your garden look great if you use these products incorrectly or pick the wrong one for the job.
If you’re like me and take pride in your garden, you want to know exactly what you’re putting into it. That’s why I’ve taken the time to find out the best weed killer for flower beds. In this article, I’ll tell you a bit about choosing the right herbicide for your needs and suggest a few of my top recommendations as well.
- Types Of Weed Killers For Flower Beds
- Best Herbicides For Flowers Gardens Reviewed
- 1. Preen Extended Control Weed Preventer
- 2. Preen Garden Weed Preventer + Plant Food
- 3. Roundup Ready To Use Weed & Grass Killer III with Trigger Spray
- 4. Doctor Kirchner Natural Weed & Grass Killer
- 5. Roundup Landscape Weed Preventer
- 6. Green Gobbler Ultimate Vinegar Weed Killer
- 7. ECO Garden PRO – Organic Vinegar Weed Killer
- Types Of Common Weeds In Flower Beds
- Final Thoughts On Weed Treatments For Flower Beds
- FAQ’s Managing Weeds In Flower Beds
Types Of Weed Killers For Flower Beds
Before deciding on a brand of herbicide you’ll need to understand the different types available. Weed killers come in different forms, have varying application methods, and may yield different results.
You should also have an understanding of your garden and the needs of your specific flowers before settling on any given formula.
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Selective Vs Non-Selective
The difference between selective and non-selective products is pretty straightforward. Some herbicides are designed to target specific plants while others target nearly all plants they touch.
A selective herbicide is designed to differentiate plants based on physical biology. All plants, including weeds, need certain environments to grow and thrive. So, for example, some herbicides will use ingredients that are very toxic to broadleaf weeds but less toxic to other kinds of plants.
A non-selective herbicide doesn’t give you the same level of control as a selective weed killer. You should be more careful in its application as it can ruin your wanted plants. A non-selective weed killer will use ingredients like glyphosate, which is toxic to both broadleaf and grassy weeds.
Natural Organic Vs Synthetic
Natural or organic formulas offer some sense of security to gardeners. If you worry about dousing your lawn in chemicals, especially when you have kids or pets playing outside, you may feel the need to consider an organic solution. Commercially produced organic weed killers contain natural ingredients such as salted water, white vinegar, and ammonium soap.
Organic weed killers are generally safer to use and environmentally friendly. However, they tend to be more effective on seedlings rather than weeds with established roots. Synthetic weed killers, on the other hand, are effective anytime you see growth.
Synthetic solutions are the norm for weed killing and will make up most of what you find in a store. As they are created in a lab, they tend to be more selective and safer for your garden plants.
They should do the job without damage when used correctly but can cause more damage to your plants than natural options if you aren’t paying attention. If you’re worried about kids or animals, you can keep them away from the area until you stop treatment.
Concentrates, Granules, & Ready-To-Use Sprays
A concentrated weed killer will say that’s what it is right on the bottle. It will usually need to be mixed with water before use and is probably more potent than the other options.
You can use it to tackle weeds that are actively growing and to cover a large area (simply make a larger mixture with more water and more concentrate). Follow the individual product’s directions for the correct mixing ratio.
Granules look grain-like. They’re usually small pellets coated with herbicide and offer a dry application option. This gives you the benefit of a longer window for use. Granules can be used on warm- and cool-season grasses. There are also pre-emergent options that work extremely well as preventative care.
Where liquid concentrate needs to be measured and mixed before spraying, granular herbicide is ready to use. However, granular weed killers usually need to be applied to a damp surface so it will stick to the weeds. Liquid weed killer can be used on your lawn anytime (though you shouldn’t apply when it’s actively raining).
Both liquid and granular weed killers need to be carefully applied to the correct areas of your garden, without overdoing it, or you risk damaging your wanted plants.
Ready to spray products have a no-mix formula that you can use right out of the bottle. These are the easiest to use as you don’t have to worry about measuring the correct ratio of water to herbicide.
Pre-Emergent Vs Post-Emergent
Pre-emergents work on weeds before they appear in your lawn or flowerbeds. While they are a good preventative method, they won’t work well on broadleaf weeds like clover or dandelions.
They also have a smaller window for application. You need to make sure you use your pre-emergent weed killers during your planting days. If you use them after growth has started, they won’t be effective. So, if you didn’t have it on hand before germination, you can’t just run out and get it later.
Post-emergents are for use on weeds you can already see. This means they can be used spring through fall, your entire growing season. When dandelions and clovers pop up, you can spot-kill them with post-emergent weed killers.
Usually, all you need to do is apply the product directly to the leaves and it will kill them to the root. You can use a post-emergent weed killer any time you see weeds in your garden. Of course, this means you need to be vigilant in monitoring your flower beds. You’ll have to remove weeds as they come instead of getting rid of the problem.
Best Herbicides For Flowers Gardens Reviewed
Now that you’re clear on the technical differences between the types of herbicides, let’s discuss the top products for your flower beds. I’ve rounded up products that have worked very well for me in the past. You should read through and compare these to find the right solution to your garden’s pests.
I’m going to talk about the quality of the ingredients, user experience, and of course, how effective each formula is.
1. Preen Extended Control Weed Preventer
Preen is a granular formula that offers a 6-month weed-free guarantee. This pre-emergent weed killer is a great way to avoid ever pulling a weed again. The top of the container acts as an applicator, so you don’t need to already own a push spreader. You apply it after mulching and then water the granules or wait for rain. That’s it.
Preen will keep the weeds away without affecting flower growth. I didn’t see a single weed for close to a year. Preen can be applied to a large area and its directed formula can be used around shrubs and trees, over 600 perennials, groundcovers, and more, as listed on the product label.
You should follow the directions carefully. I almost missed the water-to-activate step and would’ve had my weeds back. Luckily, I double-checked the directions on the bottle.
You apply it right out of the bottle. Since the smallest option is just under 5 pounds, this isn’t too much of a problem. If you need to cover more area, then you may need to buy a separate applicator so you don’t have to lug a 21-pound bottle around.
You should also remember that Preen can not be used around edible plants or plants that produce food. And, though it can be used around flowers, it should not be used on flower seeds.
When to use: Preen works best when applied after freshly planting, applying mulch, and before new weed growth. But if you didn’t use it in early spring, you can use it anytime weeds are incoming. Check for Preen Extended Control availability here
Preen Extended Control Weed Preventer can be applied up to two times per year around established plants and transplants. You can apply the first application any time throughout the growing season — spring, summer, or fall. For ongoing weed protection, a second seasonal application can be made 2 to 6 months after the first.
How to use: First, remove any existing weeds in the area. Then apply Preen Extended Control Weed Preventer using the included applicator cap. Following the amount recommended on the bottle, sprinkle the granules on top of the soil or mulch. Activate the product with water, and an invisible barrier will form on the top layer of the soil to prevent new weeds from growing.
Pros
- Selective weed killer formula that won’t harm up to 600 trees, plants and shrubs
- Guarantees a weed-free flowerbed for 6 months
- Handy flip top lid that acts as an applicator for smaller areas of coverage
Cons
- Not recommended for use around fruit, nut, and vegetable plants
2. Preen Garden Weed Preventer + Plant Food
Ok, I think Preen makes useful products and they are also number two on this list. As it says in the name, this product has the added benefit of feeding your plants while preventing weeds. The herbicide works as advertised and the fertilizer will make your flowers thrive.
The provided scoop is slightly less easy to use than the applicator lid sold with the previous formula. The smallest bucket is heavier as well but covers about 900sqft. Like with any granular herbicide, you need to store the product in a dry place. As long as moisture hasn’t gotten in, it should last for a long time.
One application lasts for up to 3 months. It is only considered safe for 200 established flowers, vegetables, trees, and shrubs, so you have to be more careful when cross-referencing your garden plantings. Just check the manufacturer’s label or their website to be sure it’s safe for your garden. Click here for Preen Garden Weed Preventer and Plant Food.
When to use: Preen Garden Weed Preventer and Plant Food can be used in spring, summer, or fall. You can use it in flower beds, ornamental gardens, around ground covers, trees, or shrubs.
How to use: Remove visible weed growth, mulch the area, apply Preen Weed Preventer and Plant Food granules, and water the area. Keep applying every 3 months or if you notice new weed growth.
Pros
- Can be used to kill weeds and feed flowering plants in one easy step
- Encourages healthy root development and bigger, brighter blooms for over 200 varieties of flowering trees and shrubs
Cons
- Not as effective as some other weed killer formulas for flower beds
3. Roundup Ready To Use Weed & Grass Killer III with Trigger Spray
Roundup is another solid brand and their liquid products work wonders. This ready-to-use weed and grass killer works at the roots to kill weeds and unwanted grasses. Their label claims it is rainproof within 10 minutes (I didn’t test in the rain), and that you can see results within 3 hours of spraying.
The bottle comes with what they call their “trigger spray” and it does make life easier. Compared to the scoop and lid above, the trigger spray lets you spray from a distance so you can stand upright for the whole application process instead of bending and scooping. As I said, I liked the trigger attachment but it might not work for everyone. My advice is to make sure it’s hooked up correctly or to contact the manufacturer if you have a problem.
This RoundUp kills everything. It’s potent and works well, which is good for weeds but bad for plants. Make sure you only spray the leaves of something you want dead in your garden, otherwise your flowers will be gone. If you use it correctly, you shouldn’t have a problem. However, you may not want to use it in a very small garden as the spray could blow onto your growing flower’s leaves.
When to use: You can use Roundup Ready To Use Weed & Grass Killer III anytime weeds are actively growing. You need to spray it directly on the leaves of unwanted plants. Be sure to spray when the air is calm to prevent drift to desirable plants. See more for Roundup Ready To Use Weed & Grass Killer here.
How to use: Spray the weeds or grasses you want to kill with the product thoroughly. If one of your garden plants is accidentally sprayed, rinse it off with water immediately. RoundUp should not be used as a spot killer on weeds in grass, since it will kill your lawn. It is safe for people and pets to enter the treated areas after the spray has dried.
Pros
- Fast acting, ready-to-use formula
- Container is fitted with handy trigger-spray applicator to reduce messy mixing
- See results in just 3 hours
Cons
- Non-selective formula which means you’ll need to keep it away from the plants you want to keep
4. Doctor Kirchner Natural Weed & Grass Killer
The first natural product on this list is also ready to use right out of the bottle. Those of you who don’t want to use a chemical compound on your garden can rest assured that Doctor Kirchner’s is made from ocean saltwater, commercial-strength food-grade vinegar, and soap.
As a herbicide for flower beds, it’s far less potent than the previous option. You can use Doctor Kirchner’s safely around your flowers. Even if you accidentally get some leaves wet, they will likely just brown without affecting the entire plant.
But that doesn’t mean it doesn’t work. I was surprised by how fast this natural solution did the trick. Weeds were browning within a few hours and soon gone. You may have to reapply more than some other options but it’s so easy to use and so effective that it’s not a problem. Use this link for Doctor Kirchner Natural Weed & Grass Killer at Amazon.com
Kirchner’s is extremely easy to use, you simply spray (garden sprayer sold separately) the liquid on the unwanted plant’s leaves until they are wet. The safety of the environment doesn’t end there. Even the jug is eco-friendly. It’s made with less plastic than its counterparts and has an ergonomically designed handle.
The acetic acid residue dissipates quickly and does not affect the soil or groundwater quality. According to their website, it’s safe for pollinators, aquatic life, pets, and children.
When to use: This biodegradable herbicide can be used anytime you have visible weeds. You can use it as a spot-killer whenever you see weeds in seams in cement and pavers, flower and mulch beds, crop beds, parking lots, and even farmland.
How to use: Apply directly to weeds anytime you see growth. Spray the weed’s leaves until wet. Wait for them to die. Remove. Repeat as needed.
Pros
- All-natural, ready-to-use formula
- Container is fitted with handy trigger-spray applicator to reduce messy mixing
- See results in just 3 hours
Cons
- Non-selective formula which means you’ll need to keep it away from the plants you want to keep
5. Roundup Landscape Weed Preventer
This Roundup product is a weed preventer. Rather than waiting for weeds to show up, you use this before you see them (pre-emergent). It’s not recommended for use on existing weeds.
Using it was easy. It comes with a built-in applicator and handles on the bag. It’s easy to apply and shouldn’t be used less than 6 months apart. It leaves very little weed maintenance. You can just leave it on top of the soil of the area you want to target. I raked it in to make sure it stuck. Then, watered and left it to work.
It works well but the reason it’s not number one is because of its limited window of use. You’ll also likely want to keep a second weed killer on hand to address actively growing weeds, in case this didn’t cover your whole garden. And, unlike the natural option, it comes with risks to people and animals. But, if everything goes well, you’ll have a weed-free season. Check Roundup availability on Amazon.com
When to use: Apply before mulching in spring and fall.
How to use: Leave on topsoil or mix in with a rake. Water to activate.
Pros
- Great for providing a weed barrier before the growing season begins
- Saves the back-breaking job of pulling weeds up
- Manufacturer provides a money back guarantee
Cons
- Only suitable as a pre-emergent weed killer and will not be effective on weeds that have already grown
6. Green Gobbler Ultimate Vinegar Weed Killer
Green Gobbler uses 20% acetic acid distilled from corn grain. It’s completely glyphosate-free and safe to use anywhere, including around kids and pets. It works on a wide range of broadleaf weeds usually in a matter of hours.
In addition to the safety aspect, no dilution is required for Green Gobbler. You fill up a sprayer and go. This is another non-selective weed killer so you should avoid using it on lawns, or desired plants.
Vinegar is naturally acidic, so it dries out plants on contact, and corn-based ethanol helps with that. Green Gobbler claims their formula is four times stronger than your table vinegar. Considering how quickly weeds died off, it certainly looks powerful. Green Gobbler Ultimate Vinegar Weed Killer is available from Amazon.com
Green Gobbler is lower on the list despite being biodegradable and effective because it can be overly effective — killing anything in its path. That’s not a problem I had but I tested the product on a calm day, so there was little spreading from the wind.
When to use: Anytime you see weed growth, use the product directly on the weed’s leaves.
How to use: Fill a pump sprayer and wet weeds thoroughly with the solution. Avoid contact with plants and flower leaves. For your flowerbeds, you should shield them with a piece of cardboard or whatever’s handy to block the spray.
Pros
- Non-selective and biodegradable weed killer
- Safe to use around pets and kids
Cons
- Keeper plants need to be protected to avoid them being dried out and killed
7. ECO Garden PRO – Organic Vinegar Weed Killer
Last to crack the top seven is another environmentally friendly option: Eco Garden Pro. This one is great largely because of its safety.
It’s OK around kids and pets and is rated as safe for groundwater. All the ingredients are Generally Recognized as Safe (GRAS) by the FDA.
ECO Garden Pro works in less than 24 hours and requires no mixing. This ready-to-use spray is easy enough to apply once you’ve bought and loaded the separate spray pump. It’s also a non-selective killer, so, like with the others, you’ll need to be careful when applying to your flowerbeds. Click here for ECO Garden PRO – Organic Vinegar Weed Killer
Overall, it works great but you’ll need to pull it out every time you see new weeds. It’s not preventative and doesn’t kill to the root, so that could be often.
When to use: Every time you have weeds.
How to use: Soak weeds in the solution, repeat as needed.
Pros
- Non-selective and environmentally friendly weed killer that’s safe to use around kids and pets
- See results within 24 hours of using
- Ready-to-use formula
Cons
- Will need to be transferred to a sprayer tank if using on larger areas
- Application will need to be repeated as it does not kill the weed’s root system
Types Of Common Weeds In Flower Beds
All of the weed killers for flower beds named here should work on any common weed you come across.
Amaranth can be ornamental or come in weed form, this annual will ruin your garden. Bindweed is a perennial climber that strangles plants. It’s common around flower beds and is hard to eliminate once established as even small pieces of the root can regrow.
The other most common broadleaf weeds have already been mentioned throughout this article. They include dandelions, thistle, chickweed, crabgrass, moss, dollarweed, and white clover.
If you have any of these in your garden, they’re easy enough to get rid of with the right weed killer.
What Is The Best Way To Keep Weeds Out Of Flower Beds?
There are some non-weed killer tricks to keep weeds out of flower beds. Closely planting flowers together, for example, can choke weeds and provide too much shade for them to grow.
Most weed seeds that germinate are close to the surface. When you remove visible weeds, try not to disturb the soil. This way new seeds don’t reach the nutrients and sunlight of the topsoil. You can do this by using a knife to cut off the heads of weeds you see.
Use drip or soaker hoses to water your plants. If you keep weeds dry, they will drastically reduce growth.
Use mulch when planting. It keeps the soil moist and cool and attracts insects that will eat weed seeds. It also prevents sunlight from reaching weed seeds. Replenish your mulch as needed and keep it about 2 inches deep.
When mulching, apply a preventative treatment and kill any weeds before they can germinate.
Final Thoughts On Weed Treatments For Flower Beds
As I said before, the best weed killer for flower beds depends on your individual needs and gardening habits. Different flowers will have different nutritional requirements and planting seasons. You should use whatever works best for your situation.
Personally, my top choice is to use the Preen Extended Control Weed Preventer to avoid weed growth for as long as you can. But I also recommend Preen Weed Preventer and Plant Food if you want to encourage your plants to grow whilst also stopping the weeds from showing up.
My third choice goes to Roundup Ready-To-Use Weed & Grass Killer III Trigger Sprayer if you want to get rid of it all — weeds, grass, and the lot! This is a super easy product to use that does not need decanting and comes complete with a trigger sprayer attachment.
