What Is Japanese Knotweed?
Japanese knotweed was brought to Britain from Japan as an ornamental garden plant in the mid-nineteenth century. However, over time it has become widespread in a range of habitats, particularly roadsides, riverbanks and derelict land where it causes serious problems by displacing native flora and causing structural damage. Due to its vigorous nature and the damage it causes it is one of only two terrestrial plants listed by the UK Wildlife and Countryside Act as illegal to cause it to grow in the wild.
Japanese knotweed is a type of plant that is an herbaceous perennial, meaning that it only grows seasonally. It does not thrive during the fall and winter. The Japanese knotweed is similar in shape to a shrub and can grow more than 10 feet (3.05 m.) tall. The plant’s six-inch (15.24 cm.) leaves are usually oval shaped or similar to a triangle in appearance. Its hollow, jointed stems boast a reddish color. During the summer, greenish-white flowers bloom on the plant. Soon, small fruits develop on the plant as well. Japanese knotweed is a swift spreading plant that quickly interferes with native plant growth. It grows in 36 mainland states in the U.S. The Japanese knotweed is a hearty plant that can overcome harsh weather conditions, including drought, high salinity, hot temperatures, and shady areas. It is often found growing along water sources, including rivers and streams, but can also be found along the road and in fields. Since the plant grows so aggressively, it can create unstabl
Japanese Knotweed is the most invasive plant known in Britain today. The plant originated in Japan where it thrives on disturbed ground. It was introduced to the UK in the early 19th Century as an ornamental plant also being used as a feed crop for cattle. The Victorian Horticulturalist who introduced the plant cannot have envisaged the devastating impact Japanese Knotweed would have. It is effectively a giant herbaceous perennial which grows at an alarming rate of up to 10cm per day in any type of soil. It forms dense clumps of up to 3m (10ft) in height. Japanese Knotweed thrives on disturbance and spreads by natural means and by human activity. Very small fragments of rhizome (underground stems), as little as 0.7g – approximately the size of a fingernail – can produce fresh new plants. But it is below ground where this invader causes the biggest problems, as each stand creates a rhizome network that can extend to 3m in depth and 7m in all directions. This makes it a serious threat to
Japanese Knotweed is a highly invasive plant and is recognised as the most invasive species of plant in Britain today. Japanese Knotweed originates from Asia and is a member of the Buckwheat family (Polygonaceae). Records reveal that it was introduced into the UK by a Victorian horticulturalist in 1824 as an ornamental plant and as a source of feed for cattle. Japanese Knotweed is now abundant throughout the whole of the UK. Although the most common and notorious Japanese Knotweed it is not restricted to one species of Knotweed, there are varients of the species which include Giant Knotweed, Dwarf Japanese Knotweed, Himalayan Knotweed, Lesser Knotweed, Russian Vine, Hedge Bindweed and Bohemica, a hybrid formed by Japanese Knotweed and Giant Knotweed Japanese Knotweed is a resilient plant that, in the UK and Europe, only spreads via the movement of its’ rhizomes. The rhizome, according to The Environment Agency Guidelines, can grow to a depth of 3m or more and up to 7m away from the pla
