About Knotweed

Japanese knotweed is a large, herbaceous perennial, introduced as a garden plant by the Victorians. It is undisputedly the most troublesome weed on the planet, causing more damage to the environment, biodiversity and property than any other. It is singularly aggressive and fast growing (up to 10cm a day), crowding out all other flora and breaking through seemingly impenetrable barriers such as tarmac, concrete and brickwork.

Like an iceberg, there is more happening out of sight, where the plants underground rhizome (root) system will penetrate up to 3m downwards and fan out up to 7m in any direction from each and every stem. This is why digging it out is usually not an option. The consequences are severe. Apart form the damage it will cause it devalues land and property. All mortgage providers now refuse to lend on property that has knotweed present. Some of the biggest even refuse to loan if it is spotted on neighbouring land. This effectively makes a non cash sale impossible until the knotweed is eradicated.

Japanese knotweed needs careful expert multiple treatments with different herbicides over many months to ensure its demise; do not believe in claims of “miracle cures”. Or for those with a huge budget, it can be dug out completely and sent to special landfill or hand sifted.