Japanese Knotweed

Lord Clark of Windermere Excerpts

Thursday 16th May 2019 Lords Chamber

[Lord Gardiner of Kimble]

We are strongly of the view that we need to look after our pollinators and insects, so we should not cut verges unless it is necessary for safety. This is certainly an issue I will take up with my Department for Transport colleagues, but I know that both Highways England and Network Rail are conscious of their responsibilities. Indeed, there have been cases in which Network Rail has been required to attend to Japanese knotweed. This is a real problem, and I encourage landowners to attend to it.

[Lord Clark of Windermere (Lab)]

My Lords, we are all indebted to the noble Lord for continuing to raise this issue. It is very serious, and many thousands of people have difficulty selling their houses because of the existence of Japanese knotweed. We all hope the bio approach works, but it will take several years. The Government cannot deal with it; it remains with the local authorities to handle it. Can they step up their efforts and advice on the herbicide approach to tackle the problem today and fill the gap before the bio approach comes in?

[Lord Gardiner of Kimble]

The noble Lord raises something really important. A very good practice manual has been published as part of a RAPID LIFE project, showing the varying ways in which this can be dealt with. They all have their issues because of the rhizome’s ability to continue, even dormant, for 20 years. Glyphosate, properly used by trained people—I emphasise “properly”—can kill Japanese knotweed in about two or three years. Biocontrol would obviously be preferable for reducing the aggressiveness of the growth, but there is a whole range of issues. I am happy to share the manual with the noble Lord.