......................you were right! Thank you.
After over a year of just leaves, and nothing else there was a spurt of growth taking it to around 4ft, and suddenly flower buds began forming which have opened out beautifully with the warm weather.
Strangely enough though many people said it had an unpleasant smell to the leaves and roots, I can't smell a thing from them, though the flower blossoms their selves smell wonderful.
As it can apparently growth through tarmac according to a couple of web pages I've read about it, I've decided to keep it in a pot and see what happens.