What is Japanese Knotweed?
Japanese Knotweed has a bad reputation and rightly so as it is one of the most common invasive non-native plant species in the UK. Japanese Knotweed was originally introduced to the UK as an ornamental plant but has spread extensively through the wild. Once rooted it is difficult to control and generates problems for our wildlife and environment because it forms in dense clumps which creates a canopy and shades out other native plants preventing their growth.
Why it is a problem?
It has the ability to grow through almost anything, tarmac, paving, cavity wall insulation, drainage pipes etc. Japanese Knotweed has the ability to affect mortgaging your house and its market value. This would make it harder to sell your property. Although you do not legally need to remove the invasive plant from your land, you may face prosecution if you allow it to spread and grow on to someone else’s land. You can be issued with a management order from the Scottish National Heritage to control the spread of Japanese Knotweed.
Control and Eradication
WCC have certified staff that offer treatments to control and eradicate this highly invasive weed. There are a number of ways to tackle Japanese Knotweed; spraying, stem injection or burning.
Spraying with chemicals (herbicides) is an effective method of treatment to stop the spreading of the plant. This can’t be carried out when it’s raining or in windy conditions and has the potential of affecting other plants and soil.
Stem injection is a treatment where the herbicide is directly injected into the lower part of the mature stems using an injection gun. This can be carried out in most weather conditions unlike the spraying method. As this method is to inject the plant it can be an environmentally friendly method of control. There’s no need to worry about the chemicals spilling into any watercourses or causing damage to any protected species/trees nearby because the measured does go directly into the stems.
Burning method is where we typically burn away the weed and has the benefit of not contaminating any other soil or plants. This requires more than one treatment as the root system can be 7 metres long and 2 metres deep. It is imperative that all the roots are destroyed to eradicate the weed.