[Aunt Sally]

Not sure if anyone knows the history, or even cares, but it was first introduced into Britain to put onto the railway embankments. The roots were used to 'bind' the soil together and stop land-slides during heavy rain and also to make it 'look green'.

I believe you are thinking of Japanese Knotweed.

[peapod]

Aunty's right..

[DD.]

Always is.

Have to say that.

[Aunt Sally]

I heard that Dave 

[blackisgreen]

someone told me to grass seed a patch then keep it well mowed it wil not come back {bit awkward on an allotment though unles you have beds} ,also told mexican marigolds and turnips get rid of it as it doesnt like root  chemicals