How to kill Japanese Knotweed. Fallopia japonica control and treatment  

Japanese Knotweed. Fallopia japonica var. japonica - Killing this invasive weed 

Japanese Knotweed has been around for years. Many many years, for as a young boy, I used to use the hollow stalks for peashooters. My friends also used to 'smoke' the dead stalks in the winter, but that is another story!

Nowadays - some 55 years on - it has become public enemy number one insofar as weeds are concerned - it is not easy to kill or control! No longer a toy, but now a serious menace - so much so that there are strict rules (laws) governing what you can and cannot do if you have the wretched weed!

 Japanese Knotweed treatment is essential as it can cost building contractors and developers dearly - sometimes many thousands of pounds if they have it on their building site. Control of Japanese Knotweed is essential.

 Furthermore, if soil removed from a building site is proven to have any trace of Japanese Knotweed, then there are hefty fines that can be imposed, together with which there can by claims for compensation if the recipient's land becomes contaminated with Japanese Knotweed. You need to know how to kill and then control Japanese Knotweed.

Killing Japanese Knotweed

It is an invasive weed - spreading relentlessly through the UK after being introduced by some unsuspecting plant hunter as a highly desirable exotic garden plant in the middle of the nineteenth century. It does not spread by seed, for it is infertile. So all of the weed crops are seen throughout the UK were spread vegetively. They started their new life as a little bit of plant - maybe just a centimetre long that was transported to the new home! This can happen by way of topsoil import, being carried by birds or animals, or even by some unsuspecting and untidy human.

Certainly the transportation of building site excavation material and debris has been a contributory factor in the spread of Japanese Knotweed - as has the moving of general garden waste and rubbish from an infected area to a landfill site and thereafter to anywhere! Waterways, railway embankments, roadside verges, building sites, and of course, gardens, are all potential home to the Japanese Knotweed (- Fallopia japonica var. japonica).

In the native habitat, Japanese Knotweed has several 'predators' ranging from certain insects and a few diseases. These keep the 'problem' confined. In the UK, no such predators exist - though experiments suggest that a small insect can now be released, which will feed on the invasive weed, and hopefully control its spread if not in time totally eradicate it. Hopefully this insect will not then turn its attention to our ornamental varieties of Knotweeds - Persicarias and Polygonum!

As a garden weed, it can cause many problems in borders, or invade lawns - where the small fragments cut up by a lawn mower can then spread to other parts of the garden. These lawn mowing can also then be transported to other areas by way of household waste, or by fly-tipping garden maintenance operatives. Not all garden maintenance firms are fly-tippers of course!

As well as being a 'weed' Japanese Knotweed is a serious problem in terms of structural damage. Once it has taken hold in ground near to buildings, it can soon cause problems of damage to buildings and certainly paved areas such as footpaths and patios. The underground stems (Rhizomes) are capable of diving down into the soil to a depth of 3 metres. Japanese Knotweed has even been found to be growing through the floorboards of a living room, after presumable growing under the foundations of the house! So - NOT to be ignored. One it takes hold, it is capable of spreading over an area of a few hundred metres within the space of a year!

If you find Japanese Knotweed (Fallopia japonica var japonica) on your land, it is your responsibility to eradicate it - kill it - control it, and prevent its further spread. It is no use just phoning the local council. It is your problem. You are responsible for your own Japanese Knotweed Control. If of course, it has been bought on to your land with a load of topsoil, or other similar provable source, then you have a claim against the persons who imported it onto your land. If you are in a new build property, and suffer from the weed, then it may well be that there is a case against your builder!
Don't try composting it, this will not kill or control it - it is a waste of time and will lead to problems if you then use that compost on your garden!