February 4, 2013

The problem with Japanese Knotweed

Japanese Knotweed poses a serious threat for land and property owners. It’s a highly invasive and destructive plant.

Japanese Knotweed can grow up to 1 meter per week and has the strength to force its way through walls, foundations, concrete and tarmac exploiting weaknesses in building, drainage systems and hard standings.

Here are some of the problems Japanese Knotweed causes:

Structural damage to buildings and foundations
Damage to paving and tarmac areas
Reduction in land value
Reduction in biodiversity
Damage to archaeological sites
Restriction of access to riverbanks
Obstructs visibility and access on roads and paths

Japanese Knotweed is spread easily through it’s rhizomes which can reach 3 meters deep and 7 meters from the root. A tiny particle of it’s rhizome, as small as 0.4 grammes, can create a new plant.

The law
Under the Wildlife and Countryside Act 1981 it is an offence to cause Japanese Knotweed to grow in the wild. Under the Environmental Protection Act 1990 Japanese Knotweed and soil containing its’ rhizome material are classified as ’controlled waste’. Therefore, when taken off site, the waste must be disposed of at special licensed sites.

An infringement under the Environmental Protection Act can result in enforcement action being taken by the Environment Agency which can result in an unlimited fine. You can also be held liable for costs incurred from the spread of Japanese Knotweed into adjacent properties and for the disposal of infested soil off site during development which later leads to the spread of Japanese Knotweed onto another site.

If Japanese Knotweed is present on your land, you have a legal obligation to contain it.

The Plant
In 1825 a Japanese Knotweed plant was imported to Britain from Japan as an ornamental. Due to its invasive and regenerative nature the species is now widespread throughout the nation. Each plant in Britain today originates from the same female specimen.

During its growing season (April – October) Japanese Knotweed can grow up to 1m in just one week. It has soft, light green, heart shaped leaves and a bamboo like stem which can grow up to 3m in height The plant will produce white flowers around September/October before dropping its leaves.

Japanese Knotweed is spread by regenerative rhizomes which can reach 3m deep and up to 7m from the plants’ shoots. Just 0.4g of this regenerative rhizome is enough for a new plant to be created making it extremely susceptible to spread by human interference. It is imperative that proper measures are taken to deal with Japanese Knotweed in order to avoid contamination and ensure its eradication.

Akers Land & Ecology offer a range of solutions to eradicate Japanese Knotweed infestations.

Herbicide treatment
Using our herbicide treatment program Japanese Knotweed infestations can be eradicated in just one growing season. Our program is based on an in-depth understanding of the plant and incorporates disturbance, cutting back and a series of herbicide applications.

On site relocation and eradication
All plant material and soil containing its rhizomes is excavated and moved to a suitable area allocated within the site where it can be isolated and treated using our herbicide treatment program.

Cell burial
All plant material and soil containing its rhizomes are excavated and deposited into a container at a suitable location on site. The sealed sealed container is buried at least 5 meters below ground level.

Removal from site
Plant material and soil containing its rhizomes are removed from site by our licensed carrier and disposed of at a special landfill site.