VIDEO: Japanese invasion shoots out from below

It was brought to Europe in mid-19th century and was much-admired for its ornamental foliage, after being uprooted from its natural habitat on the slopes of Japanese volcanoes, but it has become our most challenging invasive plant.

In 1847, it was awarded the gold medal by the Society of Agriculture and Horticulture, in Utrecht, Holland, as the most interesting new ornamental plant of the year. It was seen as a thing of beauty and was in great demand by gardeners. Once used in bouquets, people clearly thought it looked well among flowers.

Now, the very mention of Japanese Knotweed is enough to strike fear into some — it has even led to a couple’s murder-suicide in England — and its eradication is one of the most demanding tasks facing authorities in Ireland and Britain.