Top 5 Best Weed Killer That Won’t Kill Flowers – Buying Guide

The best weed killer that won’t kill flowers will keep your desirable plants healthy while removing annoying and stubborn grasses. Yet today’s market is full of options, making you confused when choosing the most suitable product for your garden.

To help you out in this issue, we share the top 5 grass killer reviews with exciting details of getting rid of weeds in flower beds.

Roundup Concentrate Extended Control Weed & Grass Killer...
  • Dual-action formula kills existing weeds and prevents new...
  • Kills weeds to the root. Guaranteed!* *Consumer Guarantee:...
  • Use on driveways, sidewalks, and patios; along fences,...

Of which, we prize the Roundup 5705010 Concentrate Extended Control Grass Killer for its exceptional performance. The weed killer boasts a dual-action formula to kill existing grasses down to their root system.

Besides, it is rainproof within 30 minutes for year-round application. It also provides effective results fast, within only 6 hours, which is quicker than most products available on the market.

Top 5 Best Grass Killer For Flower Beds Reviews

Roundup 5705010 Concentrate Weed Killer – Best Overall

Roundup Concentrate Extended Control Weed & Grass Killer...
  • Dual-action formula kills existing weeds and prevents new...
  • Kills weeds to the root. Guaranteed!* *Consumer Guarantee:...
  • Use on driveways, sidewalks, and patios; along fences,...

If you need to know how to clear weeds out of flower beds, the Roundup 5705010 Weed Grass Killer might be your answer.

It outweighs other products for excellent performance in every aspect.

The weed grass killer features a dual-action formula to completely kill existing grasses on the lawn or flower beds from the root system while thwarting new weed growth in four months.

Moreover, we are also impressed with its relatively large coverage. Coming in 32 oz weed killer concentrate, this weed control product can cover 1,600 sq ft, ideal for large areas and a big garden.

On top of that, the herbicide is also rainproof within half an hour. You don’t need to worry about the rain right after applying the grass and weed killer for flowers.

However, we highly recommend you use it in sunny weather for the best result.

This herbicide also takes effect quickly within only six hours, while most other products need 24 hours.

On the downside, we found that its tank sprayer cannot hold pressure.

What We Like

  • Dual-action formula to completely kill existing
  • Large coverage and long-lasting effect (4 months)
  • Rainproof within half an hour
  • Take effect fast (6 hours)

What Can Be Improved?

  • Tank sprayer unable to hold pressure

Preen 2464221 Extended Control Weed Preventer – Best Pre-Emergent Herbicide

Preen 2464221 Extended Control Weed Preventer, 10 lb....
  • 1 Application blocks weeds up to 6 months guaranteed
  • When used as directed Preen Extended Control Weed Preventer...
  • Can be sold as a refill for flip-top applicator

We will continue with our runner-up – the Preen 2464221 Extended Control Weed Preventer. This best weed killer can stop grasses from germinating.

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You can apply it to more than 600 plants like boxwoods, snapdragons, azaleas, ivy, daylilies, and more.

Plus, this extended control weed preventer can efficiently handle the grass issue before it becomes an issue.

The grass and weed killer for flowers is available in various containers, covering 900 square feet to 5,000 square feet.

Notably, it can block grass from growing up for six months. Another plus point is that this weed and grass killer can be applied any time of the year.

However, it is slightly more expensive than other products.

What We Like

  • Stop grasses from germinating
  • Good coverage
  • Able to use for more than 600 plants
  • The adequate time of six months
  • Year-round application

What Can Be Improved?

  • High price

Spectracide 96451 HG-96451 Grass Killer – Best For Coverage

Spectracide Weed & Grass Killer Concentrate, Use On...
  • KILLS WEEDS AND GRASSES: use on driveways and walkways, and...
  • KILLS THE ROOT: visible results as fast as 3 hours –...
  • RAINFAST: rainfall or watering 15 minutes after application...

The next position belongs to the Spectracide 96451 Weed Killer for its wide coverage. You get 64 oz of the weed killer to cover 16,000 square feet.

Another plus point of this weed killer is that it consistently performs with visible results within only three hours, even faster than the two products above. Moreover, this grass killer for flower beds can selectively kill grass in your flower beds.

To show confidence in this weed killer, the brand offers a money-back guarantee. So if you are not satisfied with this herbicide, you can ask for a money return.

That said, you will need to carefully read its instructions as it is not suitable for every grass and plant.

What We Like

  • Wide coverage of up to 16,000 square feet
  • Deliver consistent performance
  • Selectively kill grass in flower beds
  • Provide visible results within only three hours
  • Money-back guarantee

What Can Be Improved?

  • Not suitable for all weed types

Fertilome 33692 Grass Killer – Best For Formula

Hi-Yield (33692) Super Concentrate Killzall Weed & Grass...
  • Weed killer controls grasses, broadleaf weeds and woody...
  • Contains a double-surfactant formulation that dries on plant...
  • Allows you to cover and treat large areas. 32 oz. covers up...

Your flower bed will thank you if you use the Fertilome 33692 weed killer with an exclusive surfactant formula. This unique formula can help the herbicide dry on your plants and work fast.

This weed killer is also rainfast within two hours. The 41% glyphosate content kills weeds in flower beds down to their roots when used on the leaves.

After the application, you can see the results after about one week.

Nevertheless, this weed killer can kill most weeds but not as many as other options.

What We Like

  • Exclusive double surfactant formula
  • Able to dry on the plants and work fast
  • Rainfast within two hours
  • Eliminate weeds down to their roots

What Can Be Improved?

  • Not work with many pesky weeds

Ortho Weed B Gon Plus Crabgrass Weed Killer – Best For Hard Surfaces

Ortho Weed B Gon Plus Crabgrass Control Ready-To-Use Comfort...
  • Kills crabgrass, dandelions and other common lawn weeds
  • Kills weeds to the roots
  • Kills 200+ weeds

Our last pick is the Ortho Weed B Gon Plus Crabgrass Weed Killer. It wins our approval for the complete result in hard surfaces like patios, walkways, and paths.

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The grass killer can deliver a double power of root penetration thanks to the active ingredient Glyphosate.

On top of that, this pesky weed killer for lawns delivers long-lasting effects for up to one year.

This suggestion can kill existing weeds productively and thwart new weeds from growing. The only drawback is that its coverage is slightly limited.

What We Like

  • Work well on hard surfaces like patios, walkways, and paths
  • Provide a double power of root penetration to kill weeds
  • Deliver long-lasting effects for up to one year
  • Prevent new weeds from growing

What Can Be Improved?

  • Limited coverage

Comprehensive Weed Killer For Flower Bed Buying Guide

Types Of Weed Killer That Won’t Kill Flowers

Post-emergent Vs. Pre-emergent Weed Killers

The pre-emergent weed killers known as weed preventers can handle various weeds before sprouting from the soil.

Regularly, they take effect for about 6 months. Still, you have to remove all weeds in your lawn or a flower bed before using them.

Should you get some common types of weeds taking over the flower bed, such as nutsedge, it is best to use post-emergent weed killers to deal with this problem.

You had better consider elements affecting the application of herbicides for the best outcome. While pre-emergent herbicides provide the best result before spring when the weeds start to sprout, post-emergent products are ideal if you have a big issue.

Non-selective Vs. Selective Grass Killers

Should you apply a non-selective weed killer, it is best to keep this one away from the flowers, vegetation, or plant foliage you need to protect. Spray the herbicide on the grasses only as this type can eliminate all things in its way.

Although the selective herbicide might provide lower effects than non-selective grass killers, it only targets specific grasses and weeds and leaves desirable flowers to grow. It can be considered the weed killer for flower beds.

In addition, you might want to plant after you apply the grass killer. It is advisable to follow the guidelines of the herbicide before planting.

Some weed killers allow you to grow plants instantly, while some need a short waiting time.

Features To Look For


Usually, weed killers are available in 64 oz and 32 oz containers. Still, remember that grass killer containers are pure concentrated.

So they have to be diluted in the water. In other words, you will get broader coverage than you expect.

Most herbicides describe the coverage in square feet. It is best to buy more and get your work done in only one batch than purchase too little to complete the job.


What’s important to look out for is the amount of Glyphosate contained in each herbicide container.

It is known as a non-selective grass killer. In other words, it can remove everything on a flower bed on its path and even down to its roots.

Glyphosate is quite dangerous if you are exposed to it frequently. It is best to take precautions to prevent exposure to this harsh chemical.

You can wear gloves to deter it from touching the skin and use safety goggles to keep the chemical from splashing to the eyes.

Indeed, there are also other chemicals found in the herbicides. The best idea is to take precautions irrespective of what to save your family and you from the risks of the harsh chemicals.

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When considering a weed grass killer, you had better check if it comes with a “rainproof” feature. It shows how long it takes for the herbicide to resist the rain.

Water and rain dilute any chemicals and lessen the effectiveness of the herbicide.

If it starts to rain soon after you apply the herbicide, the weed killer can be diluted. As a result, it cannot remove pesky weeds as expected, requiring you to reapply it in several days.

If your area is moist or rainy, you need to choose weed killers with short rainproofing periods. Some are even rainproof in about 10 minutes.


Weed killers might be slightly expensive. Still, it depends on if you plan strategically or not. Below are several tips you can consider.

  • Additional cost: If you have a tight budget in grass care, it is best to consider other costs when buying a herbicide.
  • Purchase based on the needed coverage: You can receive discounts when buying in bulk for various products.

So it will make sense to purchase a weed grass killer container in gallons compared to buying small weed killer bottles.

Remember that you do not need to purchase a massive amount of herbicide to cover the entire yard. All you need is to target where you want to kill grasses.

Effective Period

Some will be effective within only several hours after the application. Meanwhile, others can take some days or even weeks to show some signs of the grass withering.

So it is best to consider your needs to kill the grass when choosing a weed grass killer.

Here’s how to kill weeds without harming your bedding plants:

Frequently Ask Questions (FAQ)

What is a good weed killer that won’t harm plants?

Roundup 5705010.

A common weed killer that’s non-selective and won’t harm plants is Roundup 5705010. If you do not want to use herbicide spray, consider cutting weeds close to the ground and applying a vinegar solution around the base of undesirable plants. 

Vinegar can help sterilize the roots but does not eliminate them altogether. It will take time for them to come back if this technique is used often or combined with other methods such as mulching or pulling weeds out.

If your garden is small, these techniques might work better than using a chemical herbicide spray. But if your garden is large, it’s best to use an herbicide spray because many areas may need treatment at once.

Can you spray weed killer near plants?

Yes. Separate the weed killer from the plant by a barrier.
If you use a herbicide that is “contact sprays” as opposed to those with “systemics,” it’s sufficient to follow those instructions closely about working from the back of the leaf so as not to disturb or harm any sensitive parts of the leaves or flowers. 
In addition, some weed killers will have special instructions about how far apart the plants should be sprayed and on produce what can handle exposure. 
Follow all instructions carefully and move away from any on-target plants before spraying any off-target weeds near your garden beds.


So you have gone through our best weed killer that won’t kill flowers. In short, our winner is the Roundup 5705010 Concentrate Extended Control Grass Killer for its wide coverage and fast, effective results.

Again, before you buy a weed killer, it is best to consider the critical factors like coverage, ingredient, pricing, and effective period.

Anyway, we hope our article is helpful for your consideration. Should you have any questions, please feel free to let us know.

Thank you for reading!

Top 5 Best Weed Killer That Won't Kill Flowers - Buying Guide
Top 5 Best Weed Killer That Won't Kill Flowers - Buying Guide
Top 5 Best Weed Killer That Won't Kill Flowers - Buying Guide
Top 5 Best Weed Killer That Won't Kill Flowers - Buying Guide

Last update on 2024-06-07 / Affiliate links / Images from Amazon Product Advertising API

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Jill Sandy

I am a sustainable focus gardener. I love decorating my home backyard with beautiful landscape design and creative garden care techniques I develop myself.