How To Prevent Japanese Knotweed From Spreading

japanese knotweed

Japanese Knotweed (also known as Fallopia Japonica), is among the most invasive plants in the United Kingdom. It grows very rapidly and spreads easily by rhizomes and stem fragments. It is considered a major problem because of its’ strong root system which can cause damage to foundations, buildings, drains, roads, and other structures.

In the UK, legislation obliges all landowners to prevent spread of Japanese knotweed onto the neighbouring property, and it classifies dug or cut materials as controlled waste which should only be disposed of at the specified landfill sites. Well, you don’t have to remove the knotweed from your garden, but you may be prosecuted if you let it spread onto someone else’s property. In this article, we are going to discuss ways on how to prevent Japanese Knotweed from spreading with help from Japanese knotweed specialists;

Chemical Control

This is the use of specialised herbicides over a certain period of time, usually 3 years. It’s one of the most economical measures and causes the least disruption, especially in residential areas where space is limited and the property boundaries are located close to each other. Remember consent is needed if the chemicals are to be used near water bodies. The majority of the chemicals used are glyphosate-based products, which normally eliminate the portion of the plant that’s above the ground, causing dormancy of the rest of it. It’s important to note that, it may take up to 3 years to treat Japanese knotweed until underground rhizomes are dormant.

Stem Injection

This method involves injecting a dose of glyphosate herbicide into individual canes using specialized equipment for treatment and eradication of the Japanese Knotweed. This method is usually more time consuming, but it helps prevent the chemicals coming into contact with the other plants or any nearby water bodies.

Root Barrier

Root barrier systems is another method that can be used to prevent Japanese knotweed from spreading. This method involves installing an impenetrable barrier which stops the Japanese Knotweed from spreading onto the neighbouring gardens as its’ root system (ie. rhizome) will not be able to penetrate that barrier. The root barrier should be installed at a 45-degree angle so that any root growth from outside of the barrier will be directed downwards instead of punching through it. Japanese knotweed specialists can advise on this process.

Burying It

This involves excavation of the entire plant and the roots, to a depth of about 5 metres, and then burying it in a properly sealed and a bunded receptacle area. It should be buried at a depth of no less than 5 metres. Ensure you cover the plant’s remains with material that doesn’t allow any growth through it. Before burying it on your land, make sure you check with the Environment Agency so as to see if that is allowed.

Burning It

This method involves removal of the entire plant and its’ roots, and then burning it. When burning it, keep in mind that Japanese knotweed will only be effectively incinerated if the plant is completely absent of moisture (meaning, the plant’s strands need to be completely dried out). Once you have done this, you can proceed to burn the plant. Dispose any remaining material properly, in case the rhizomes or the crown survive burning.