The need to identify Japanese Knotweed

As someone once said – know your enemy.  And Japanese Knotweed certainly isn’t your friend.  So the first step is correctly identifying it.  

What it is:

Japanese Knotweed is fast-growing perennial plant that can grow at an alarming rate, in many cases as much as 10cm a day. It is no respecter of boundaries or ecology, so it needs to be addressed at the earliest opportunity.

It spreads by root systems (known as rhizomes) being disturbed and moved – and you might not even know you’re doing that, as the active elements are so small.  In fact, as little as 0.7 grams (less than the size of your fingernail) is all that’s needed for a new infestation of Japanese Knotweed to develop on your land.

Why that’s a problem:

Japanese Knotweed can grow through foundations exploiting existing defects, which ultimately leads to a reduction in their value – no ifs or buts. Its aggressive nature means it creates its own monoculture, pushing out native species by reducing localised biodiversity. 

As a result, lenders will typically refuse to engage with a property that has an infestation of Japanese Knotweed – unless an effective management programme is in place, and one that includes an Insurance Backed Guarantee. 

Thankfully, that’s where we come in.

Recognising Japanese Knotweed on your land

There are various stages of growth with regards to Japanese Knotweed which can be identified as follows:


  • Initial growth has red and purple shoots with rolled back leaves which develop rapidly.
  • Can look almost like an asparagus tip in the early stages of development.


  • Stems are almost bamboo like with green stems that include purple speckles. 
  • The stems form a zig-zag formation and are hollow.
  • The leaves have a ‘shield’ like appearance with a flat back to the leaf along with a pointed tip.
  • In late summer creamy-white flowers will hang from the stalk to form a cluster.


  • The stems will turn brown and become brittle retaining the zig-zag formation.
  • The leaves will wilt and begin to turn yellow.


  • Stems will lose all colour and become woody. 
  • They can easily become detached from the crown from which they originally developed.
  • All leaves will be brown but will retain their ‘shield’ like shape.

Japanese Knotweed Crowns

Japanese Knotweed crowns are formed over several growing seasons and are characterised by their wood like blocky appearance.  Typically, they will have the base of the stem still attached to them which will have a small hollow circular appearance.  Crowns are not always evident on immature infestations or on land that has seen the Japanese Knotweed disturbed.

For more photos that can help you identify Japanese Knotweed, check out our comprehensive Image Gallery here.

Commercial Services

  • Full site surveys within 48 hours of you calling us.
  • Nationwide coverage – we’re local, and we’re national too!
  • Tailored cost effective solutions.
  • A 10-year warranty with options for a separately underwritten Insurance Backed Guarantee, for additional peace of mind.
  • Full detailed SMART management plans that help secure planning permission and finance.
  • Lump sum pricing with no hidden extras – delivering proven value for money .

Residential Services

  • Conduct a no obligation full site survey of your property or land.
  • Produce a comprehensive management plan for submission to your mortgage lender or planning officer.
  • Issue a competitive fixed price lump sum quotation – with no hidden extras – for guaranteed eradication along with our price promise. 
  • Offer interest free payments over the program to help with budgeting.
  • Issue a 10-year warranty that covers any potential regrowth – with the offer of a separately underwritten Insurance Backed Guarantee – available on all projects.

What our customers say

It’s easy for us to tell you how effective, responsive and professional we are, but it means more to hear it from our satisfied clients. And that’s all of them.

There’s a certain comfort in knowing that when you attend a client meeting at a site to quote for works, that the person with you has the confidence, professionalism and knowledge in the industry that is going to help secure that job. That is what Inspectas deliver.

Brian Whitcher – Client Services Manager – GRITTIT

I tasked Inspectas with helping me secure a re-mortgage on the family home that has a Japanese Knotweed infestation to the rear garden.  No sooner had they been out to complete the survey I had all the relevant reports and guarantee information submitted to my mortgage company for approval.  A week later and one of their technicians was underway getting rid of knotweed for us.  They absolutely delivered what they promised!

Tony – Residential

Facilities Management is all about being able to be reactive and having the right plans in place to deal with a given problem. Inspectas Land Remediation are our go-to business when we come across Japanese Knotweed issues on site. They are quick to react and their ability to rapidly adapt and put forward workable solutions is a quality we highly value. Their absolute professionalism is second to none.

Robin Harris – Managing Director – Velway

Whenever one of my clients have a problem surrounding Japanese Knotweed or other invasive weed issues I always refer them to Inspectas Land Remediation.  Their ability to provide bespoke solutions and put actions in place that make a difference is a quality my clients value and appreciate.

Chetna Reay – Managing Director – Construction Risk Consultants Ltd

Very comprehensive work, we thank you for an excellent service all round.

Malcolm Turley General Manager, Day Services, Teesside Ability Support Centre

Prevent Japanese Knotweed taking over your land!

Get in touch today

If you think there may be knotweed on your land – or if you want to request a quote or survey – there are several ways to contact us. Just choose which one works for you.

… or let us call you back

Need an expert’s opinion or got questions about our services? Want us to check a photo of some suspect weeds on your land?

Submit your details here – and add a pic if you want – and we’ll get right back to you.

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Phone us on 0800 288 4967

Text / WhatsApp photos to 07494 678440

National offices in:

Birmingham, Bridgewater, Canterbury, Cardiff, Chelmsford, Leeds, Liverpool, Newcastle, Nottingham, London, Southampton.

Remember, you should never try to treat Japanese Knotweed
yourself as this could cause the infestation to spread.

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