Hi does it has it flowered yet.im thinking Himalayan balsam if it. is it need getting rid of before it does flower other wise you will have it all over next year.see what others say though.good luck.

There is no flowers yet and I did chop off one on the top bit then more side shoots come out from it. thanks

Its seed pods can shoot seed out very far from the plant. Are there more than one in your garden and have they ever flowered before? They all must be dug out with pickaxe and shovel... roots and all

Thanks Loosestrife2 I will try to cut it down now, much appreciated

I'd poison it if you can its an invasive weed

Having checked I suggest you do too, its a government site concerning invasive weeds and what the rules are if its on your land,
Basically its trouble if you allow them to escape it seems

Thanks Pamg, I did put weedkillers after I cut it down as no way can it been dug up as the ground is clay and solid hard. I will look out for it next year.

If you use a translocated weedkiller like glyphosate in the spring when its growing strongly then the poison will be taken to the roots quickly
You may need more than one application!