It needs the sun, Motinot. You're right about taking a year to flower - and it'll need to be taken under glass in the winter, as it's a tender plant. If you cut it back - no flowers next year! It normally dies after flowering, so I've read...but if you collect the seeds, it's easily grown, apparently!

All this came from the RHS book - I haven't grown it myself.

I've tried to grow it several times. One of the problems is that it makes a VERY big plant and as it needs protection from frosts you need to give it winter cover. In a BIG pot that can be a problem.
They grow particularly well in the Scilly islands as well as Madeira!
It can look very scruffy after the first winter, but then starts to grow back well. But not easy unless you have the sheltered space.
Good luck.

...So let it die back naturally and place it under cover for the winter....Ok thank you both for the information...:>)

It shouldn't die back over winter but remain at the size it has grown this summer. The leaves may go a bit yellow and die back a bit during the winter but then the plant should start into growth again vigorously to produce the big flower spike.
So bring it under cover before any frosts.

Ok...Thank you very much Bertie....I have a sun-room...not very big but i shall have a go at over-wintering it...:>)