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Best Herbicide For Japanese Knotweed (2024 Updated)

If you're looking for an effective solution for Japanese Knotweed, you're in the right place. Japanese Knotweed is a highly invasive plant that can cause significant damage to your property. It can grow up to 10cm per day and has a resilient root system, which makes it difficult to control. So, it's crucial to choose the right herbicide to manage it.

Before buying any herbicide for Japanese Knotweed, there are some factors to consider. Firstly, you must ensure that the herbicide is specifically designed for Japanese Knotweed. It's because these plants have insurmountable resistance, and you need a severe solution to counteract it. Secondly, you should read reviews and details about the herbicide carefully. You need to know the time it takes to work, how frequent you should use it and the application methods.

Are you struggling with Japanese Knotweed? Are you fed up with using ineffective solutions? If yes, fear not! We have searched and found an exceptional herbicide that can do wonders for you. Are you interested in knowing what it is? Stay tuned and keep reading to learn more about our favourite herbicide for Japanese Knotweed.

10 Best Herbicide For Japanese Knotweed

# Product Image Product Name Product Notes Check Price
1
Ideal for controlling weeds and unwanted vegetation in agricultural and non-crop areas, including roadsides, industrial sites, and pasturelands.
2
The product is ideal for preventing weed growth before it emerges.
3
This product is ideal for controlling weeds and invasive plants in turf grass and non-crop areas.
4
This product is ideal for effectively killing weeds and unwanted plants in a concentrated form.
5
The product is ideal for controlling and eliminating aquatic weeds or plants in various bodies of water.
6
This herbicide is ideal for selectively controlling grass in a variety of landscapes, such as golf courses and ornamental turf.
7
Professional pre and post-emergent weed killer for lawn and turf grasses.
8
It is ideal for chemical synthesis and as a reagent in various laboratory applications.
9
Ideal for selectively killing weeds in lawns without harming the grass.
10
This product is ideal for killing nutsedge (nut grass) in established lawns, ornamental turfgrass, and landscape areas.
Ideal for controlling weeds and unwanted vegetation in agricultural and non-crop areas, including roadsides, industrial sites, and pasturelands.
The product is ideal for preventing weed growth before it emerges.
This product is ideal for controlling weeds and invasive plants in turf grass and non-crop areas.
This product is ideal for effectively killing weeds and unwanted plants in a concentrated form.
The product is ideal for controlling and eliminating aquatic weeds or plants in various bodies of water.
This herbicide is ideal for selectively controlling grass in a variety of landscapes, such as golf courses and ornamental turf.
Professional pre and post-emergent weed killer for lawn and turf grasses.
It is ideal for chemical synthesis and as a reagent in various laboratory applications.
Ideal for selectively killing weeds in lawns without harming the grass.
This product is ideal for killing nutsedge (nut grass) in established lawns, ornamental turfgrass, and landscape areas.

1. Navigate A Selective Herbicide, 50 Lbs,

Applied Biochemists Navigate A Selective Herbicide is an ideal solution for controlling aquatic weeds like milfoil, stargrass, bladderwort, lily, coontail, watershield, water chestnut, spatterdock and more. It is an effective herbicide that works well when broadcast evenly using a spreader or blower. In case of small spot treatments, it can be applied uniformly using a hand scoop or spreader.

This herbicide is made up of special heat-treated attaclay granules that resist rapid decomposition in water. It ensures long-lasting protection from weed growth and keeps the aquatic area clean and healthy. However, it is important to note that this product is not suitable for non-turf irrigation and drinking (human consumption).

This 50-lb container of Navigate A Selective Herbicide is a reliable and cost-effective solution for aquatic weed control. It is not eligible for shipping to AK, CT, HI, ME, NJ, NY, WA, or Canada. Any orders placed from these states will be cancelled.

Pros

  • Effectively controls a variety of aquatic weeds
  • Easy to apply using a spreader or blower
  • Special heat-treated attaclay granules ensure long-lasting protection
  • Cost-effective solution for aquatic weed control

Cons

  • – Not suitable for non-turf irrigation and drinking (human consumption)
  • – Cannot be shipped to AK, CT, HI, ME, NJ, NY, WA, or Canada

2. Ranger++ranger+pro+glyphosate++herbicide++concentrate++2.5+gal.

Glyphosate-41% is an effective herbicide that contains the same active ingredient as Roundup. It is ideal for use in residential areas, parks, and recreational areas to control unwanted weeds and grasses. Glyphosate-41% is easy to use and can be mixed with Ranger Pro at a rate of 2-3 ounces per gallon of water.

Glyphosate-41% is a systemic herbicide that works by penetrating the leaves and roots of the plant, killing it from the inside out. It is rainfast in as little as 30 minutes, so you don't have to worry about rain washing it away. Glyphosate-41% is also non-selective, meaning it will kill any plant it comes into contact with, so be careful when applying it near desirable plants.

Glyphosate-41% is an affordable and efficient way to keep your outdoor areas looking their best. Its fast-acting formula will quickly eliminate weeds and grasses, leaving your lawn or garden looking neat and tidy.

Pros

  • Contains the same active ingredient as Roundup
  • Ideal for use in residential areas, parks, and recreational areas
  • Easy to use
  • Rainfast in as little as 30 minutes
  • Affordable and efficient

Cons

  • – Non-selective, meaning it will kill any plant it comes into contact with

3. Airmax Shoreline Defense Aquatic Herbicide – 1 Quart (32 Ounce)

The Broad Spectrum Emergent Weed Control is a highly effective systemic herbicide that can take care of even the most persistent weeds. It is specifically designed to kill the roots of emergent weeds such as cattails, phragmites, lilies, and purple loosestrife with ease. This product is perfect for cleaning up beaches, shorelines, and other areas affected by invasive weeds.

With just 1 quart of Broad Spectrum Emergent Weed Control, you can treat an area up to 10,000 square feet, making it a cost-effective solution for large-scale weed control. It is important to note that this product cannot be shipped to AK, AZ, CA, CT, DC, HI, ME, NJ, NY, PR, RI, VT, WA or Canada.

Broad Spectrum Emergent Weed Control is a great choice for anyone looking for a powerful and efficient solution to weed control. It is easy to use and provides long-lasting results that will keep your outdoor spaces looking clean and weed-free.

Pros

  • Highly effective systemic herbicide that kills the roots of even the most persistent weeds
  • Works great on cattails, phragmites, lilies, purple loosestrife & other emergent weeds
  • Perfect for cleaning up beaches & shorelines
  • 1 quart can treat up to 10,000 square feet, making it a cost-effective solution for large-scale weed control

Cons

  • – Cannot be shipped to AK, AZ, CA, CT, DC, HI, ME, NJ, NY, PR, RI, VT, WA or Canada

4. Bayer Acclaim-Extra Selective Grass Herbicide

Acclaim Extra is a highly effective selective post-emergence herbicide that is specially formulated to control both annual and perennial grasses in commercial and residential turf, sod farms, and ornamental settings. Its active ingredient, fenoxaprop-p-ethyl, is present in a concentration of 6.59% and is known for its powerful herbicidal properties.

This herbicide is an excellent choice for those looking to effectively manage a variety of grasses including barnyardgrass, crabgrass (both large and smooth), goosegrass, foxtail, panicum, and even johnsongrass in its seedling stage. Its powerful formula targets the grasses while leaving the surrounding ornamental plants unharmed.

Acclaim Extra is easy to use and can be applied using a variety of application methods including backpack sprayers, handheld sprayers, and spray rigs. It is important to follow the application instructions carefully to ensure optimal results.

Overall, Acclaim Extra is a highly effective and versatile herbicide that is perfect for those looking to maintain beautiful, healthy turf and ornamentals. Its powerful formula, ease of use, and excellent results are sure to impress even the most discerning users.

Pros

  • Highly effective selective post-emergence herbicide
  • Controls both annual and perennial grasses in commercial and residential turf, sod farms, and ornamental settings
  • Active ingredient fenoxaprop-p-ethyl present in a concentration of 6.59%
  • Targets a variety of grasses including barnyardgrass, crabgrass (both large and smooth), goosegrass, foxtail, panicum, and johnsongrass in its seedling stage
  • Easy to use and can be applied using a variety of application methods
  • Leaves surrounding ornamental plants unharmed

5. Weed Be Gone Pro Concentrate.

Looking for a highly effective herbicide? Look no further than Liquid Harvest Mesotrione! This powerful product is designed to prevent the germination of crabgrass seeds and kill broadleaf weeds on contact. It works by inhibiting photosynthesis in susceptible plant species, with a 40% active ingredient that is distributed throughout the plant after being absorbed by roots, shoots, and leaves.

Liquid Harvest Mesotrione is a versatile herbicide that targets 46 broadleaf species of weed and grass, including Barnyard grass, Carpetweed, Chickweed, Clover, Crabgrass, Dandelion, Foxtail, Goosegrass, Henbit, Yellow Nutsedge, Purslane, Thistle, Wild Carrot, and more. It is safe for use on Kentucky Bluegrass, Centipede grass, Buffalo grass, Tall Fescue, Perennial Ryegrass, Fine Fescue, and St. Augustine Grass (grown for sod only). However, it should not be applied on Bentgrass, Poa annua, kikuyugrass, zoysiagrass, seashore paspalum, or bermudagrass, except for dormant bermudagrass.

To use Liquid Harvest Mesotrione, simply mix 4-8 oz. with 30 gallons of water per acre and apply with a surfactant for maximum effectiveness. Be sure to read the label for full instructions. Keep in mind that Mesotrione is not your typical weed killer. While it will absorb and start working immediately, it can take up to 2-3 weeks before full death occurs on your weeds. In addition, Mesotrione must be activated by water. If rainfall hasn't occurred within 10 days of application, water the area with 0.15 inches of water.

Pros

  • Prevents crabgrass seed germination
  • Kills broadleaf weeds on contact
  • Allows cool season turfgrass to grow in a weed-free environment
  • Targets 46 broadleaf species of weed and grass
  • Safe for use on various grass types

Cons

  • – May take 2-3 weeks before full death occurs on weeds
  • – Requires activation by water

6. 25ml Pyrrolidine ≥99% Cas 123-75-1 Acs Grade

The Pyrrolidine ACS Grade is a high-quality chemical compound with a purity of 99%. It is commonly used in various industrial applications and is known for its versatility and effectiveness.

This chemical compound has a CAS# 123-75-1 and is also known as Tetrahydropyrrole. Its IUPAC name is Pyrrolidine, and its chemical formula is C4H9N. The molar mass of Pyrrolidine is 71.123 g/mol, making it a relatively lightweight compound.

The Pyrrolidine ACS Grade appears as a colorless liquid, making it easy to distinguish from other chemicals. Its clear appearance also makes it easier to use in various applications, as it does not affect the color of the final product.

Pros

  • High-quality chemical compound with a purity of 99%
  • Known for its versatility and effectiveness
  • Relatively lightweight compound with a molar mass of 71.123 g/mol
  • Appears as a colorless liquid, making it easy to distinguish from other chemicals

7. Gordon’s Speedzone Lawn Weed Killer, 20 Ounces, 652400

The Reseed Two-Week Weed Control is perfect for large property owners who want rapid and effective weed control. It covers from 14,000 to 18,000 square feet and provides visible results within hours. This product is specifically designed to target common and troublesome weed species in turfgrass, ensuring that your lawn remains healthy and weed-free. Moreover, it does not harm lawn grasses, making it safe to use in any lawn. The Reseed Two-Week Weed Control is also ideal for use in cool weather conditions, ensuring that your lawn remains healthy even during the colder months. Please note that this product is restricted in certain states and cannot be shipped to AK, DC, MA, NJ, and VT.

Say goodbye to stubborn weeds with Reseed Two-Week Weed Control. This powerful formula provides visible results within hours and covers a large area, making it perfect for large property owners. You can rest easy knowing that this product is safe for your lawn grasses, and it won't harm them in any way. The Reseed Two-Week Weed Control is also designed to work in cool weather conditions, ensuring that your lawn remains healthy and weed-free throughout the year. Please be aware that this product is restricted in certain areas and cannot be shipped to AK, DC, MA, NJ, and VT.

Achieve a weed-free lawn in no time with Reseed Two-Week Weed Control. This product is specifically designed to target common and troublesome weed species in turfgrass, providing rapid and effective weed control. It covers a large area, making it perfect for large property owners. The Reseed Two-Week Weed Control is also safe for your lawn grasses, and it won't harm them in any way. It's designed to work in cool weather conditions, ensuring that your lawn remains healthy and weed-free all year round. Please note that this product is restricted in certain states and cannot be shipped to AK, DC, MA, NJ, and VT.

Pros

  • Provides visible results within hours
  • Covers a large area of 14,000 to 18,000 square feet
  • Rapid and effective weed control for common and troublesome weed species in turfgrass
  • Does not harm lawn grasses
  • Designed to work in cool weather conditions

Cons

  • – Restricted in certain states and cannot be shipped to AK, DC, MA, NJ, and VT

8. Atticus Nut Grass Killer – 1.33 Oz.

Empero is a trusted herbicide that contains 75% halosulfuron-methyl, which is the most effective active ingredient for controlling tough nutsedge. This herbicide provides a total nutsedge takedown by traveling down to the root system tubers for complete top-to-bottom weed kill. You can use Empero on nearly any established warm- or cool-season turf, including bluegrass, fescue, Bermudagrass, zoysia, and more, with confidence.

Measuring and mixing Empero is simple. Add one level scoop of Empero and two teaspoons of surfactant to a gallon of water, and the rapid dissolving granules make fast work of thorough mixing. After applying the spray solution, pets and people can re-enter the treated area once it has dried, allowing you to enjoy your outdoor space quickly.

Empero sets quickly, making it ready for unpredictable weather. It is rainfast after four hours, so you don't have to worry about a sudden shower washing away your treatment. However, Empero is not available for sale in Alaska, Maine, Montana, or North Dakota due to state restrictions. Always read and follow label instructions, as not all products are registered for use in every state.

Pros

  • Contains 75% halosulfuron-methyl, the active ingredient trusted by professionals for controlling tough nutsedge
  • Provides a total nutsedge takedown by traveling down to the root system tubers for complete top-to-bottom weed kill
  • Gentle to most established warm- or cool-season turf, including bluegrass, fescue, Bermudagrass, zoysia, and more
  • Simple to measure and mix with rapid dissolving granules
  • Pets and people can re-enter the treated area once the spray solution has dried
  • Sets quickly and is rainfast after four hours

Cons

  • – Not available for sale in Alaska, Maine, Montana, or North Dakota due to state restrictions

Best Herbicide For Japanese Knotweed FAQs

Are there any herbicides that are safe for surrounding plant life while targeting Japanese knotweed?

Yes, there are herbicides that are safe for surrounding plant life while targeting Japanese knotweed. One such herbicide is glyphosate, which is a non-selective herbicide that targets the leaves and stems of the plant. Glyphosate is absorbed by the plant and transported to the roots, where it kills the plant. However, glyphosate can also harm surrounding plant life if it is not applied correctly. It is important to follow the application instructions carefully and to avoid spraying on windy days or when rain is expected. Another herbicide that can be used to target Japanese knotweed is imazapyr. Imazapyr is a selective herbicide that targets only certain types of plants, including Japanese knotweed. It can be applied directly to the plant or injected into the stem, and it is generally safe for surrounding plant life. However, as with any herbicide, it is important to read and follow the instructions carefully to minimize the risk of harm to other plants or wildlife in the area.

How long does it take for an herbicide to kill Japanese knotweed?

The time it takes for an herbicide to kill Japanese knotweed depends on several factors such as the type of herbicide used, the size of the knotweed, and the environmental conditions. Typically, it takes 2-3 weeks for the herbicide to start showing its effect on the knotweed. However, it may take up to 3-5 years for complete eradication of the plant.

Glyphosate-based herbicides are commonly used for controlling Japanese knotweed. These herbicides work by inhibiting the growth of the plant and eventually killing it. It is important to note that the herbicide should be applied during the active growth phase of the knotweed for effective results.

The size of the knotweed is also a crucial factor in determining the time it takes for the herbicide to work. Smaller plants are easier to control and may take lesser time than larger plants to show results. Additionally, environmental factors such as temperature, moisture, and sunlight can also affect the effectiveness of the herbicide.

Overall, the time it takes for an herbicide to kill Japanese knotweed varies depending on these factors, and it is recommended to consult a professional for effective control and eradication of this invasive plant species.

Is it possible to completely eradicate Japanese knotweed with herbicide treatment?

Japanese knotweed is a highly invasive plant species that can cause significant damage to buildings, roads, and other infrastructure. There are various methods to control and manage the spread of Japanese knotweed, including herbicide treatment. However, eradicating Japanese knotweed completely with herbicide treatment alone may be challenging.

Herbicides are effective in controlling the growth and spread of Japanese knotweed, but they may not completely eradicate the plant. Eradicating Japanese knotweed requires a long-term approach, which may involve multiple rounds of herbicide treatments over a period of several years. Additionally, herbicide treatments should be combined with other management practices, such as excavation, burial, or burning of the plant material, to ensure effective control.

Furthermore, the effectiveness of herbicide treatment depends on various factors, such as the timing of the application, the type of herbicide used, and the size and age of the plant. Therefore, it is best to consult with a professional weed control specialist to determine the most effective treatment plan for eradicating Japanese knotweed. Overall, while it may be challenging to completely eradicate Japanese knotweed with herbicide treatment alone, it is possible with a comprehensive and long-term approach.

What are the best practices for applying herbicide to Japanese knotweed?

When it comes to applying herbicide to Japanese knotweed, there are a few best practices that should be followed to ensure the most effective treatment. First and foremost, it is important to use the correct herbicide and to follow the manufacturer's instructions carefully. Glyphosate-based herbicides are often recommended for Japanese knotweed, but other options may also be effective depending on the situation.

Timing is also crucial when applying herbicide to Japanese knotweed. The best time to treat the plant is in late summer or early fall when it is actively growing and transporting nutrients to the roots. This is when the herbicide will be most effective at killing the plant and preventing regrowth.

Proper application techniques are also important for successful treatment of Japanese knotweed. The herbicide should be applied evenly and thoroughly to all parts of the plant, including the leaves, stems, and roots. It may be necessary to apply multiple treatments over a period of several years to fully eradicate the plant.

Finally, it is important to take precautions to prevent the spread of Japanese knotweed during and after herbicide application. This may include using protective clothing and equipment, avoiding disturbing the soil around the plant, and properly disposing of any plant material that is removed during treatment. By following these best practices, it is possible to effectively control and eradicate Japanese knotweed using herbicide treatments.

What is the most effective herbicide for controlling Japanese knotweed?

Japanese knotweed is a highly invasive plant species that can cause significant damage to buildings, roads, and other infrastructure. Therefore, it is essential to control its growth by using an effective herbicide. The most effective herbicide for controlling Japanese knotweed is glyphosate. Glyphosate is a non-selective herbicide that kills all types of plants it comes into contact with, including Japanese knotweed. Glyphosate works by inhibiting the production of an enzyme that is essential for plant growth. It is essential to apply glyphosate at the right time and in the right quantity to ensure its efficacy. The most effective time to apply glyphosate is during the plant's active growth period, which is typically from June to September. Additionally, it is important to follow the manufacturer's instructions carefully when using glyphosate to ensure safety and effectiveness. Overall, glyphosate is the most effective herbicide for controlling Japanese knotweed and should be used with caution and care.

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