How Did Japanese Knotweed Take Over Britain?

Simply put, Japanese Knotweed is Britain's most invasive non-native plant. 

Fallopia Japonica was originally brought back to the UK back in the middle of the 19th century by the Victorians, specifically by a German-born botanist named Philipp von Siebold. He found it growing on the side of a volcano, and planned to use it as a beautiful ornamental plant that could be used in residential gardens.

This discovery was widely celebrated, so much so that the plant was named the 'most interesting new ornamental plant of the year' by the Society of Agriculture and Horticulture at Utrecht in Holland. Back in the UK, Japanese Knotweed was noted for its beauty and potential use as animal feed.

The plant was sold commercially by nurseries

In 1854, a shipment of various plants including Japanese Knotweed was sent to the Royal Botanic Gardens in Kew by Siebold. This shipment was shared with the Royal Botanic Gardens in Edinburgh in 1854, and this is where the plant started to spread as it was then sold commercially by nurseries.

The main pattern of distribution was through purposeful planting and distribution, although this was before its destructive power was known. Japanese knotweed spread naturally as well, making use of water courses and often transported in soil during construction or road-building. Ann Connelly, an expert in knotweed, stated evidence from the 1960s showed the plant had been deliberately placed in Welsh coal-mining valleys as it was good for stabilising loose soil.

In its native Japan, the volcanic landscape combined with erratic climate and regular deposits of ash keep the plant in check. It is only able to survive thanks to its deep root system - and it is this root system that can cause huge problems back in the gardens of the UK. With nothing to fight against, Japanese Knotweed in your garden can grow unchallenged with devestating consequences. At its most aggressive, this is a plant that can grow up to 20cm per day, break through concrete or tarmac and push its roots 3m deep. It has the strength to overpower almost all other plants, totally swamping them and preventing them from getting any light. 

Safely removing both the plant and its roots is much tougher than simply digging it up, as doing this can risk the spread of rhizomes - tiny fragments of stem and root that can float across to other areas of your garden where the problem will begin all over again. Contact us to remove, treat and prevent Japanese Knotweed in your garden.