How to Terminate and Control the Spread of the Japanese Knotweed

Japanese Knotweed Under Treatment



Are you looking for the safest way to remove or terminate the Japanese Knotweed? Are you living in UK and facing Japanese Knotweed problems? If yes, this is your lucky day. This article by Japanese Knotweed Expert addresses Japanese knotweed removal using both natural and artificial methods. So far, the Japanese knotweed present in the United Kingdom has not yet been able to produce active seeds. Unfortunately, the hybrids of this weed can produce viable seeds.

So, what exactly is Japanese Knotweed?

This weed has been around for more than five decades and has been a major public enemy. It’s not easy to control or kill (due to the fertile hybrids). The Japanese Knotweed is a robust-growing clump forming perennial plant. Once fully grown, it develops tall dense annual stems which renew annually from the stout.

This weed spreads vegetatively from the stem, crown and rhizome. The sad part is that it a new plant can grow from a tiny piece of rhizome, stem or crown.

Removal and control of the Japanese Knotweed

Non-chemical techniques

Even though this option is safe for the environment, it can lead to other problems. For instance:

· You might dig out the rhizomes as much as possible but re-growth will always occur. These rhizomes penetrate deep into the ground. Digging the weed out creates problems as it goes against the Environmental Protection Act 1990. This act requires the weed to be disposed at licensed landfill sites.

· If you prefer digging the weed out, you should remove as much root as possible and destroy any re-growth. This will exhaust the energy reserves remaining in the rhizomes gradually. This process might take several seasons.

Biological control

This technique requires you to plant a plant sucker (psyllid) where the weed is growing. Unfortunately, this plant sucker is still under trial hence not available to gardeners. If successful, it will be released to the public.

Chemical control

Weed-killers are most effective when the user follows the instructions on the pack. This will also minimise risks to the environment and people. The most popular and yet simplest weed-killer is known as glyphosate. It has to be applied to the cut canes. You might also use other strong formulations of glyphosate such as Scotts Tumbleweed, Doff Maxi Strength, Bayer Tough Rootkil, etc.

· Apply glyphosate to the foliage as it will be passed to the weed’s underground parts.

· During winter, cut away old stems as this allows good access. Just like other weeds, the best time to spray the Japanese Knotweed is during its flowering stage or late summer.

· If the height of the weed is more than 2.1m, spraying will be difficult. Just let the weed to grow to about 90cm and spray it.

· It takes at least 3-4 seasons to completely terminate the Japanese Knotweed using glyphosate.

DOs and DONTs


Start treatment as soon as you notice the weed on your property. The larger it grows, the harder it becomes to terminate.

Ensure that you get to the root of the problem.

Before using chemicals, ensure that you understand the herbicide treatment fully.


If you need guarantee, don’t perform DIY work.

Never allow the weed to spread to neighbouring properties.

Don’t spread contaminated soil.


The Japanese Knotweed has been a major problem in the United Kingdom. If you notice any signs of this plant on your property, alert your neighbours and seek professional help if need be.

Leave A Reply

Your email address will not be published. Required fields are marked *