invasive exotic Japanese spores
The Japanese knotweed (the Fallopia Japonica) is, as the title implies, an invasive exote. Invasive means that the (exotic) plant has major consequences. The definition of invasive is here to read back.
The knotweed family has many variants. The most famous varieties are buckwheat and rhubarb. To date, only the Japanese knotweed is known to do a lot of damage to foundations, sewerage and paving. The roots of the plant make their way underground and are therefore a danger to buildings. Every day, the rhizomes can grow underground centimeters (up to ten, twenty centimeters per day). The roots are strong enough to break through asphalt and the rhizomes can grow up to seven meters long!
Strangely enough, the plants are still available for sale in Dutch garden centres. And are used even in floral arrangements.
Origin of Japanese knotweed
The Japanese knotweed, the name says it all, comes from Japan. In 1825, the Japanese knotweed was introduced into Europe by the Horticultural Society of London. The plant was then called Houttuyania cordata. On the website of bestrijdingduizendknoop.nl can also be read that the plant was brought to the Netherlands between 1829 and 1841 by the German researcher Jonkheer Philipp Franz Balthasar Von Siebold. The plants were then grown in Leiden and spread throughout Europe. The Japanese knotweed was sold as an ornamental plant.
Articles on damage
Many articles have been published on the damage that the Japanese knotweed can do. Here is a small selection of all media messages:
Dangerous Japanese knotweed just for sale: do not put them in the garden
The Japanese knotweed takes over the country
NRC checks: Knotweed grows right through electrical cabinets
NRC Checks: Japanese Knotweed Reduces House Value by 80 percent
Asphalt breaking Japanese knotweed conquers Groningen
The danger of the Japanese knotweed
Beware of the Japanese knotweed
Fight against proliferating Japanese knotweed along A27 takes four years
Great financial damage and hardly stoppable; the Japanese knotweed
Platform: stop sales Japanese knotweed
