Tall red stemmed plant?

[Jeannine]

I have a very tall red stemmed plant and I have no idea what it is. I know it'll grow about 5 - 6' tall. The stems and leaves are a burgundy color and I believe the flower will be like a plume. Help. What is it?

[ianmunt]

Tree peony ??

[hammerman]

Red cordyline ?

[Robinia]

Rogersia?
Are you sure it'll be quite that tall?

[Robinia]

oops, sorry, wrong spelling...should be rodgersia

[s2ike]

A picture would be useful but it could be Japanese Knotweed.
This is a plant you do not want.
It is very invasive and will take over your garden and your neighbours gardens. It will grow through concrete.
It has to be sprayed to kill it. You cannot dig it up and dispose of it other than to a licensed waste disposal site which will cost. If you cut it down, burn the cuttings. It is illegal to dump it. It will regenerate from the smallest piece of root material.
Have a look on the internet, particularly www.environment-agency.gov.uk there is a lot of info about it and you will be able to identify if the plant you have is this horrible thing.
I hope I am wrong!
David