Japanese knotweed removal

Cost-effective Japanese knotweed removal & treatment methods for residential and commercial sites with insurance-backed guarantees

Japanese knotweed is described by the Environment Agency as “indisputably the UK’s most aggressive, destructive and invasive plant”

Due to the powerful root and rhizome system, which extends deep into the ground, knotweed is notoriously difficult to treat or remove without professional help – and failure to do so could result in your property being damaged and devalued

Identification of Japanese knotweed

Accurate identification is key. You’ll find a useful video and photos here to help you identify knotweed through the various seasons – send a photo to our FREE identification service and we’ll confirm if it’s knotweed.

The devil is in the detail. It’s imperative to know what type of knotweed it is, the maturity, extent, and condition of the underground rhizome and root system – and the ground conditions in which it is growing. That is why a site survey is often required. Knowledge is key; armed with this information a suitable Japanese Knotweed Management Plan (JKMP) can be devised that has the highest chance of success.

Japanese knotweed leaves

How do you eradicate Japanese knotweed?

As you might expect, Japanese knotweed eradication is a specialised service – and even expert firms now steer away from the term “eradication” because even we can never be 100% certain that it is completely eradicated – and therein lies the importance of the guarantee. Yes, you can try to do it yourself but don’t be surprised if the weed appears again pretty quickly after you think you’ve got rid of it. It can be backbreaking work to try and dig up all of the roots and, depending on the ground is often all but impossible without using mechanical aids such as an excavator.

Over the last 25 years, our team at Environet has developed a range of different methods for Japanese knotweed treatment and removal. Residential areas often need highly specialist approaches when it comes to Japanese knotweed eradication, mainly because buildings and gardens are smaller and closer together. At Environet, we use a couple of different trademarked approaches to remove Japanese knotweed including DART and Resi-Dig-Out (a scaled-down version of our commercial Eco-Innovative Xtract).

If you want to get rid of Japanese knotweed without using herbicide, Resi-Dig-Out is a great choice. The good news is that it’s cheaper than many of the traditional approaches, diverts a lot of waste from landfills, and leaves your garden in a useable condition pretty much instantly.

Our treatments for Japanese knotweed have been developed over many years, using the latest technology and our own experience. Of course, our specialists will need to take a closer look at your property and the extent of the infestation before they decide which approach is best. The aim is to make sure all rhizomes are treated or removed, leaving your property and surrounding areas clear.

What our clients say

What our clients say

Is the guarantee important?

Absolutely, yes. Mortgage lenders will want to see an insurance-backed guarantee for up to 10 years from a reputable specialist (e.g. Accredited members of either PCA or INNSA). This has implications for those who attempt DIY methods. We provide insurance-backed guarantees for up to 10 years, backed by an “AA-“ rated insurer, meaning that if there’s regrowth post-treatment – you’re covered.

What makes our insurance-backed guarantee market-leading?

  •  “AA-” rated insurer accepted by all major lenders.

  •  Up to £100,000 limit of liability.

  • Optional cover for property damage resulting from regrowth.

  •  Cover effective in days – no delays.

  •  Up to 10 years’ cover.

  •  No excess charges.

  •  Fully assignable.

  •  Minimal restrictions.

Japanese knotweed solutions

  • Physical Removal – Excavation and removal of the underground root and rhizome system, ensuring Japanese knotweed is gone, and gone for good.
  • Herbicide Treatment – This is a control method, as while herbicide can kill immature plants, it’s less effective on mature rhizomes, often causing dormancy rather than death.
  • Combination Methods – A combination of physical removal, herbicide treatment, and the use of root barriers is often the optimum solution.

Find out more about our treatment and removal options here:

DART™ Combination Solution

The tried and tested DART™ method (Dual Action Residential Treatment) from Environet is the most cost-effective combination removal & treatment solution for Japanese knotweed on residential properties.

Excavator next to house


With Environet’s unique Resi-Dig-Out™ method a property can be knotweed free in a matter of days at any time of year.

Herbicide treatment

Knotweed Herbicide Treatment

Herbicide treatment is a popular control method because it has the advantage of being relatively low cost, and is effective if done correctly.

Japanese Knotweed in a garden flowerbed

Surveys and Management Plans

In order to identify the best removal method for your property, our expert surveyors need to complete a comprehensive survey. 

How much does Japanese knotweed removal cost?

There are many factors that can affect the cost of removal for Japanese knotweed, including the chosen removal method, quantity of affected land, site-specific conditions, and more. To find out more, click here to read our latest blog discussing the factors that affect removal costs.

Area affected Lower limit Upper limit
5m £2,100 £12,000
25m £3,250 £30,000
50m £3,500 £60,000

A table detailing the typical cost range of Japanese knotweed treatment/removal EX VAT across the industry in 2023, based on total visible area.


Can I treat or get rid of Japanese knotweed myself?

If you’re tempted to treat it yourself, consider these points:

  • Most people attempting a DIY solution will fail, making subsequent professional treatment more complicated and expensive.
  • Using chemicals purchased from a garden centre or DIY store will rarely be strong enough to kill the underground root system, and will often result in dormancy which means that even if the plant appears to be dead above ground, the underground rhizome remains very much alive ready to regrow at any moment.
  • Damage to other prized plants may be caused by poor herbicide application.
  • DIY treatment won’t provide you with much of a legal defence if it spreads into your neighbours’ land.
  • Digging out the rhizome system is difficult; it’s best left to professionals.
  • You won’t get the all-important insurance-backed guarantee which could make it very difficult to sell your property in the future and adversely affect its value.

Does Japanese knotweed affect property value?

The simple answer is Yes. You’re legally obliged to disclose whether the property is “affected” when selling and mortgage lenders will impose conditions that could prompt a buyer to renegotiate or even walk away. But don’t panic, a professionally prepared and actioned Japanese Knotweed Management Plan normally returns the value close to the “non-affected” value. Check out this online calculator to get an idea of how your property’s value might be impacted.

How much Japanese knotweed have I got?

To determine the knotweed infected area in sq m on a subject property measure/approximate the length and breadth of the visible Japanese knotweed at ground level. Multiply the length x breadth to give you the total visible in sq m. As knotweed rhizome spreads laterally underground the actual area of infestation is greater than is visible above ground. A buffer zone is therefore added in each direction to the visible length and breadth of 1m in normal circumstances, and 2m or more in exceptional cases.

For example, a stand of visible knotweed measuring 2m x 1m with a buffer of 1m in each direction would be 4m x 3m, to give a total of 12 sq m. It is not necessary to add the buffer if the buffer falls outside of the property boundary. So for example, if the above was in the corner of the garden, the area would be 3m x 2m, to give a total on the subject property of 6 sq m.

If there are 2 stands of Japanese knotweed within 2m of each other, it is likely that these are interconnected underground and should be classed as 1 stand when measuring the length and breadth.

How can I be sure that I have knotweed?

That’s easy – just email us your pictures! Environet offers a free, same-day identification service. Just send us some close-up pictures to [email protected] and we’ll let you know if it’s knotweed you’re dealing with. Once we’ve checked the pictures, we can talk you through the next steps.

Japanese knotweed isn’t always visible to the naked eye, for example during winter when the plant dies back, or if it’s been herbicide treated in the past it may be lying dormant beneath the ground and could begin to regrow at any moment. Sometimes people try to deliberately conceal knotweed, for example by laying a patio over it.

This is why, the best way to achieve peace of mind is always to call a removal specialist!

Why should I deal with Japanese knotweed?

It’s perfectly legal to have Japanese knotweed on your property, so this is a worthy question. Here are the main reasons why a property owner should tackle knotweed growing on their land.


Protect your assets

Knotweed will make it more difficult to sell an affected property, impacting its value by up to 10%. Half of would-be buyers will walk away from a property known to be infested with knotweed. Sellers are required by law to disclose the presence of knotweed – if they don’t, they risk an expensive misrepresentation claim in the courts.


A growing problem

Knotweed is programmed to grow, its underground rhizome system extending year on year, infecting more ground. It’s a problem that simply won’t go away on its own, so the sooner it’s tackled the better.


Nuisance neighbours

Knotweed does not respect property boundaries and those who allow it to spread also diminish the value of their neighbour’s property. This can lead to neighbour disputes and costly civil claims under private nuisance legislation.



Knotweed can and does cause damage to property. Perhaps not as bad as some might make you believe, but don’t underestimate the damage the plant can wreak.


DIY disasters

Knotweed and building or landscaping projects don’t mix! If you want to add that conservatory, summer house, or home office pod to the garden, tackle the Japanese knotweed first. 


The heavy hand of the law

And for those who are still not convinced, be aware that an injunction or Community Protection Notice, otherwise known as an ASBO, can enforce people to act to remove knotweed from their property.


Our team of experts is available between 9am and 5:30pm, Monday to Friday to answer your enquiries and advise you on the next steps

Want a survey?

If you already know you have an invasive plant problem, you can request a survey online in less than two minutes by providing a few brief details. A member of the team will swiftly come back to you with further information and our availability.

Need quick plant identification?

Simply upload a few images of your problem plant to our identification form and one of our invasive plant experts will take a look and let you know, free of charge what you are dealing with. We’ll also be there to help with next steps where necessary. 

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