6 Best Weed Killer For Japanese Knotweed In 2024

The best weed killer for Japanese knotweed should fully eradicate the vegetative and the rhizomes of this weed. By being a 100% invasive weed, mechanical control is not enough to eliminate this notorious weed.

Herbicide for knotweed should kill both the vegetative part and the rhizomes parts of this weed. However, to safely and timely eradicate Japanese knotweed from your property, considers going Japanese knotweed herbicides that are safe to use around kids and pets.

Below find our typical Japanese knotweed herbicides/ weed killers available today!

Reviews:6Best Weed Killer For Japanese Knotweed 2024

1.Roundup Japanese Knotweed & Grass Killer Iii Trigger Sprayer, 1 Gal.

Roundup, which is comfortable and ready to use knotweed herbicides, requires no measuring or mixing. For effect, the result considers using these herbicides in cloudy and cold climatic conditions.it is rainproof for 10 minutes. As a result, it works excellently in rainy or snowing regions leading to Japanese knotweed control success stories.

View on Amazon

By being a non-organic product, no harmful chemicals are released to the environment. Also, it does not release toxic aerosol sprays to the ground. Hence it is an eco-friendly knotweed herbicide. This round tends to effectively control other grass or broadleaf weeds present in walkways, driveways, or even patios by being a liquid knotweed killer.

Moreover, the availability of ready to use sprayers was the main reason as to why Roundup Trigger Sprayer, one gal herbicide as our preferred Japanese knotweed controls Herbicide. Storing the remaining weed killer is very easy as it comes in an airtight container.

  • Light in weight
  • Ready to use
  • Budget-Friendly
  • 10 minutes of rainproof
  • None

2.Martin’s Eraser Max Super Concentrate 1gal

Next up, find Martin’s Eraser Max Super, which comes with 78% imazapyr and 4.68% Glyphosate as the significant ingredient. The two components (which are plant growth regulator) will eradicate all the Japanese’s knotweeds prevent either in your driveways, patios, or driveway or sidewalk cracks.

View on Amazon

Additionally, the 78% imazapyr ingredient plays a vital role in killing mature and young Japanese knotweed rhizomes effectively. It comes with not only quality but an airtight container.

Martin’s Eraser will also kill other broad and grass weed present in your lawn or fence lines. It is also safe to use around household m, pets, and kids are it does not cause an allergic reaction.

It comes with proper packing that ensures that these herbicides’ content is free from water and excess heat. For significant results, consider using these herbicides early in the morning or slightly later in the evening when the weather is calm.

  • Liquid Herbicide
  • Effective
  • Ready to use
  • Organics product
  • Not 100% natural.

3.Compare-N-Save 016869 Concentrate Grass And Weed Killer

The third is the Japanese knotweed herbicides on our list, as it is both Cost-effective and 100% Aquatic approved. By being a cost-effective way of controlling knotweed, the gallon herbicides can effectively cover an area of more than 25,000 square feet.

View on Amazon

On the that have by being aquatic approved, you can use this knot wee herbicide in areas sounding water bodies in your yard. It comes with   41 % glyphosate as the primary active ingredient. It comes with quality sprayers.

But why did we feature Compare-N-Save on the knotweed herbicides list? Well, Compare-N-Save has to access magical powers from glyphosate. Therefore, it can eradicate young and mature knotweeds.

Also, the glyphosate can kill both deep and show knotweed rhizomes either in rocky or moist areas. By coming with   41% glyphosate, Compare-N-Save made it to be our overall best glyphosate weed killer for Japanese knotweed currently available on the market today.

  • Glyphosate rich
  • Non-allergic
  • Easy to administer
  • Midrange product
  • Causes itchiness
  • Higher dosage to treat knotweed in a large area

4.The Andersons Snapshot Dg Knotweed Pre-Emergent Killer/Herbicide

It does not release harmful aerosol or carbon compounds to the atmosphere. As a result, it is one of the most influential and eco-friendly knotweed killers on our list today. It also comes with a quality foaming nozzle, making sports knotweed treatment too easy to achieve.

View on Amazon

Interestingly, it is also ready to use the product as no prior assembly is needed. Another exciting feature of this product is that the packaging material can be easily recycled; it has a long residual effect. As a result, it is a perfect long term natural knotweed control agent.

Moreover, it is a non-irritant knotweed herbicide, hence safe to use around kids and pets. Anderson is also a 100% self-incorporating granule; therefore, fore it is the only weed killer on this list, effectively enough to eradicate all the knotweeds roots and rhizvely.

Lastly, being a selective knotweed killer, this Andersons Pre-Emergent killer/Herbicide effectively controls other 111 plus broadleaf weeds. It has   Spherical shape granules, which makes it easy to flow from the wrapping bag .furthermore, it is also a water-soluble granular weed killer hence formulation of this Herbicide can easily be combined with grass fertilizers.


  • Soluble in water
  • Granular weed killer
  • Great flowability
  • It can cover 25,000 square feet.


  • Not 100% rainproof
[/su_list][/su_box][/su_column] [/su_row]

5.Bonide Burnout Concentrate, Fast Acting Knotweed, And Grass Killer (1 Qt.)

Forth on our list, find Bonide Burnout Concentrate, a 100% non-selective and fast-acting Japanese knotweed herbicide. If accidentally ingested, wash your mouth with running water and consult your doctors.

View on Amazon

The only downside of bonide burnout concentrates Herbicide that it kills both broad and narrow leaf weeds. A high percentage of the total ingredient of this weed killer is natural materials as results. As a result, despite bonide being a non-selective weed killer, it is also a natural product.

It does not release harmful compounds to the environment. Hence an eco-friendly and Japanese knotweed killer, for significant results, consider using these weed killers under 40 degrees Fahrenheit. It has glyphosate as the active ingredient; hence it will effectively control the entire Japanese knotweed around your house, fence lines, and even driveway cracks.

  • Light in weight
  • Easy to store
  • Soluble in water
  • Kills a broad spectrum of weeds
  • Non-selective weed killer

6.Southern Ag Crossbow32 Japanese Knotweed & Brush Killer

Sixth on our list, find CROSSBOW32, which is a quick-acting and eco-friendly Japanese weed and bush killer from Southern Ag. Coming with 2, 4-dichlorophenoxyacetic acid as the active ingredient, southern Herbicide instantly kills young and mature knotweed rhizomes.

View on Amazon

Additionally, butoxy ethyl ester, an active ingredient in this Southern Ag CROSSBOW32, has a systemic effect on knotweed leaves and roots. As a result, it causes knotweed to wilt and dies after 24 hours of formulations.

Moreover, it was the only herbicides that contain triclopyr on our list. Therefore, Southern Ag weedkiller to control Japanese knotweed in the yard or driveway. Also, it has a high concentration as the 4 to 6fl. Oz can give a concentered 3 gallons of water.

However, triclopyr causes allergic reactions to both pets and kids. Consider using it away from the household.  These weed killers’ selective nature allows it to be compatible with grass pastures and non-crop gardens or beds.

  • Controls all weeds
  • Commercial grade
  • Easy to use
  • Non-burning formula
  • Not 100% organic
  • Toxic to pets

                       How To Get The Best Weed Killer For Japanese Knotweed 2024                      

Getting rid of Japanese knotweed cost is going higher every other day as this weed is also evolving and adapting to most of the herbicides available today. Also, there are hundreds of weed killers available on the market yet not compatible with Japanese knotweed.

Eradicating knotweed can take time. As a result, consider going for herbicides that have a more prolonged residual effect. This weed has a highly invasive characteristic as it can achieve a height of 2 meters within weeks. Knotweeds use rhizomes as the primary mode of propagation; thus, they tend to remain on the ground and spread more quickly.

Long-Term Effectiveness

Herbicides that have a slightly long residual effect play a vital role when controlling knotweed. Herbicides that have long-term effects should also be giving a top priority. These herbicides have a better ability to eradicate the troublesome.

On the other hand, consider going for a high percentage of active ingredients to ensure. Herbicide

Granular knotweed Weed Killer

There is both granular and liquid weedkiller. The only difference between the two products is the mode of applications. In case you are looking for knotweed killers that can be compatible with fertilizers, then consider going for granular herbicides.

When controlling knotweed in large and windy areas, consider going for the granular types as they are more effective and easy to formulate.

Liquid knotweed Weed Killer

On the other hand, liquid Japanese’s knotweed herbicides are not compatible with windy areas are high. Liquid weed killers are highly effective. The only downside of the liquid weed killer is that they should be formulated late in the evening or early in the morning when the weather is slightly calm.


It would help if you also considered when picking a prime knotweed weed killer is to consider going for a budget-based product.

Additionally, going for budget knotweed killers prevents you from breaking the balance of your bank. Ensure you are familiar with your budget as there are both cheap and price effective weed killers on the market.


Lastly, consider being familiar with the knotweed weedkiller brand. Consider going for a weedkiller label that has no adverse effect on your skin to your breathing system.

Consider going for organic labels herbicides as they are non-allergic products. Moreover, knotweed herbicides should be non-staining. This feature ensures that cleaning your work gear or pavements will be 100% easy.


Japanese Knotweed is a considerable challenge. Both homeowners and landscapers are challenging to control and very invasive. If you are looking for only the best weed killers for knotweed, you can comfortably consult our list as all the products are high performance and have long-term effects.

A knotweed free lawn or yard is not only attractive but also safe for your pets and kids to thrive. Additionally, controlling knotweeds reduces nutrient compatibility between the weed and either your grass or flowers.


1.Farming  independence 

2.Purdue extension



"I'm Rob a keen Botanist & Horticulturist, passionate about home gardening, lawns, yards, and orchards. What's your favorite? Let's get to work!"

Recent Posts