Wednesday, 5 December 2018

It’s a knotty problem

As the national and parliamentary debate about Brexit continues, I often take wry amusement from the contributions of some arch-Brexiteers about the way in which we need to return to “our British way of life”.
I heard one such contributor on the radio recently speak with proud anticipation of his ‘traditional British Christmas dinner’, apparently with little understanding of the origin of the varieties of food which appear on that plate.
Of course, turkeys were originally imported from China, potatoes were brought by the Spanish from South America, sprouts were first grown in Ancient Rome and then in Germany and Belgium long before they reached the UK, sage and onion came from Mediterranean countries, carrots variously from what is now called Afghanistan and Turkey, and the raisins and sultanas for our Christmas puddings were from the grapes cultivated in Greece, Turkey and what we used to call Asia Minor, sweetened by sugar from cane grown in the Caribbean and flavoured with spices from the East Indies. So far as I am concerned, our diet and food has been vastly improved by these imports.
Similarly, there are thousands of plants which enhance British gardens and parks which had their origins thousands of miles away. The wonderful British institution, Kew Garden, is now the repository of tens of thousands of seeds from plants and trees from throughout the world.
However, there are a few plant imports which we could do without. In particular, there are three non-native species which have caused serious damage to our environment, the economy and occasionally to our health.
Giant Hogweed and Himalayan Balsam caused havoc with the environment, especially around rivers and streams. They crowded out other plants, changed the habitat and nature of water-courses, and deleteriously impacted on local ecologies, especially the diversity of small mammals, fish and insects.
But it is Japanese Knotweed which has most often been the focus of attention in urban areas, as it thrives in places where the native flora is already impoverished. The rhizomes (roots) have an ability to travel a long way underground before the two metre stems and large triangular leaves surface.
So big a problem did it become that its control was specifically addressed in the 1981 Wildlife and Countryside Act. Under Sec 14 of that Act, it is an offence to plant or cause Japanese Knotweed to grow in the wild. A magistrates’ court can impose a maximum fine of £5000 or a maximum prison sentence of six months, or both. A Crown Court can impose an unlimited fine or a maximum prison sentence of two years, or both.
Although not a statutory nuisance, allowing Japanese Knotweed to spread onto neighbouring land could be considered to be a private nuisance. This means that if you had Japanese Knotweed on your land and you allowed it to spread to neighbouring land, the owners of that land could take civil action against you.  That is why you will find that if you are selling land or trying to insure your home, you will be asked to make a declaration about Knotweed.
Under the 1990 Environmental Protection Act, Japanese Knotweed is ‘controlled waste’ and must be safely disposed of at an appropriately licensed landfill site. Contaminated soils must be buried to a depth of at least 5 metres. All waste producers to ensure that a written description of the waste and any specific harmful properties is provided to the site operator.  Other regulations also apply.
So, there are strict legal requirements applying if you have Japanese Knotweed on your land, and it can be very costly both to ignore it and to deal with it.
However, some people have questioned whether the physical and environmental damage caused by Japanese Knotweed is as great as previously claimed and whether its existence is over-regulated.
That is why the all-party Science and Technology Committee has decided to hold a short inquiry, specifically to explore the science behind the effects of Japanese Knotweed on the built environment.
The Committee has invited expert submissions on the following issues by Monday 31 December:
  • What scientific evidence exists on the effects of Japanese Knotweed on the built environment;
  • How the presence of Japanese Knotweed in the UK affects mortgage lending decisions and property valuations;
  • Whether mortgage lending decisions relating to the presence of Japanese Knotweed are currently based on sound scientific evidence of its effects on the built environment; and
  • What guidance for the sector currently exists, the impact of existing legislation, and how else evidence-based responses to the presence of Japanese Knotweed can be encouraged.
You can submit written evidence at
But the Committee is also interested to hear from people about their experiences of dealing with Japanese Knotweed, whether as a homeowner, tenant, prospective purchaser or developer. You can tell the Committee about your personal experiences by completing a dedicated webform at
It’s certainly a knotty problem. You can help decide how it is dealt with in the future.