Japanese Knotweed Root System

Share This Post

Table of Contents

The Root of the Problem

Japanese knotweed is a highly invasive species of plant that thrives in the summer months. In the UK, it can be found throughout England, Scotland and Wales.

This weed grows at an accelerated rate during the summer months, and its growth can be problematic for local flora and fauna as well as for the property owner. If left unchecked, Japanese knotweed can stunt the growth of other plants in your garden and cause damage to your home’s structure.

Japanese knotweed can do more than just stunt local flora and fauna—it can also be detrimental to your financial situation. It can prevent mortgage offers from being processed, as well as cause property damage when left unchecked.

It is considered an offence to cause Japanese knotweed to grow in anywhere, especially in the wild. This means you have responsibility in controlling and managing the spread of this weed.

Japanese knotweed is often introduced to a new area by mistake, as people fail to identify it as a weed. It spreads easily and can grow in almost any environment. It’s important to identify the weed, then control it before it spreads. Once established, Japanese knotweed can spread quickly and become a major problem.

Identifying Japanese Knotweed

Check out our free identification service or find out how to identify Japanese Knotweed.

Japanese knotweed identification is essential. This hardy perennial grows into tall stems that reach 7ft in height, but its root structures are what cause the most damage.

Because of its distinctive features, Japanese knotweed can be easily identified. In spring and summer, it has cream flowers, large leaves and reddish stems that look like bamboo. In later summer or early autumn, it develops up to six inches long milky-white shoots. The thick stems grow quickly and look similar to bamboo.

Tell Me More About the Roots!

To eradicate Japanese knotweed, you must focus on its roots. If left unchecked, the roots will continue to spread and cause damage.

Japanese knotweed roots grow from rhizomes, which can burrow deep underground and appear as tough, wood-like trunks. These often clump together or collect in larger, densely packed ‘crowns’.

Rhizomes have a brown, orange-hued trunk. When cut, the inside of the trunk appears orange. Cutting off rhizome pieces and pulling them from the soil is ineffective at best because the rhizome tends to break into smaller pieces, which then regrow and spread. Large-scale removal can require heavy machinery or chemical applications.

Rhizomes are modified roots that spread horizontally, typically establishing themselves underground and spreading quickly. They are able to sprout new stems from their nodes, which can quickly reach the surface and further how this weed develops above ground.

Unlike seeds, which are dispersed by wind, water or other external forces, rhizomes spread via plant reproduction. But experts often associate rhizomes with more thuggish and invasive species of weeds that have a reputation for aggressive and rapid growth. Complete eradication means digging up remnants of the root system and preventing future outbreaks by removing all traces of previous growth.

Find out more about our residential and commercial services.

Getting to the Root of it

Rhizomes are vigorous, green, fibrous roots that spread up to 3 metres deep in the ground and grow up to 20cm thick. They can develop in large patches and can even burrow beneath the surface of the soil. Rhizome growth is aided by the plant having enough time and space to mature.

Japanese knotweed, with its cream flowers and thicker stems, is identifiable by sight above ground. However, it spreads and develops just as vigorously underground as it does on the surface. The weed is troublesome because it can develop a root system year-round, even when it dies back in the winter.

So, What are the Methods of Removal?

Japanese knotweed is difficult to eradicate because its roots spread over a wide area and can survive underground, even in frozen soil. The weed’s invasive nature often necessitates a more complex approach to weed removal than other species.

In order to eliminate this troublesome invasive weed, professional techniques are recommended. Our new electronic removal service is safe, quick and cost effective—read more about it here. Other solutions include the use of root barriers or chemical treatments like Stem Injection, which rely on concentrated doses of Glyphosate Herbicide injected into the stem to eradicate Japanese knotweed.

Other techniques, such as those using detection dogs, have been effective in identifying the presence of Japanese knotweed in areas with restricted access, such as beneath overgrown vegetation.


Japanese knotweed is a tough weed to control, but with the right approach it can be controlled, treated and eradicated.

If you’re a veteran gardener, controlling Japanese knotweed may seem especially difficult if it’s actively spreading underground. If you try to remove the weed yourself, whether manually or chemically, you may risk leaving rhizomes behind. If this happens, Japanese knotweed will continue to spread and cause damage.

So how do you get rid of this pesky plant? Start with our  Japanese knotweed identification service. You can also give us a call and speak to one of our Japanese Knotweed Specialists.


Are your pictures on a different device? Don’t have pictures available at the moment? No problem! Sending pictures to us is EASY at ANYTIME. You can contact us via the following:

SMS Text






1 Step 1
Fill in the form below, attach your pictures and we'll let you know if the plant in your picture is Japanese Knotweed.

Please choose from one of the following:

By sending this form I consent to let Knotweed Services (UK) Ltd collect and store the personal data contained in the above form submission, so that they can respond to my enquiry. 

FormCraft - WordPress form builder

More To Explore

Table of Contents Introduction Japanese knotweed is the most invasive species of knotweed in the United Kingdom. The pernicious perennial continues to …

With the long and cold winter of 2017/2018, the growing season for Japanese Knotweed has been delayed. We would normally see the …

ARE YOU SURE ABOUT THAT? Did you know the characteristics of Japanese Knotweed significantly change when it has been treated incorrectly! Let …

We use cookies to give you the best online experience. We do not pass over any personal information to 3rd parties via our cookies. If you do not accept cookies, our website may not display or function correctly.

Privacy Settings saved!
Privacy Settings

When you visit any web site, it may store or retrieve information on your browser, mostly in the form of cookies. Control your personal Cookie Services here.

These cookies are necessary for the website to function and cannot be switched off in our systems.

In order to use this website we use the following technically required cookies
  • wordpress_test_cookie
  • fc_sb_1

Decline all Services
Accept all Services