I wish I had a pound for every time this one is asked! It's a Shoo Fly or Nicandra physalodes, spreads by seed freely (except in my garden).

Thank you so much Cammomile. Now I know, seeds given to me by another member of my flower club a few years ago. I don't remember planting them unless they were mixed up with something else.
Something is eating the top leaves but the flowers are very pretty anyway.

They are pretty I just can't get them to grow.

Well I didn't do anything special. These were seeds in a 4" pot and potted on to 5". Just normal compost started them off. I tried some in the garden last year and got nothing so forgot about them. I have a couple of "stragglers" about three ins. high if you want one.

That's very kind of you Thorneyside, but I just don't have an inch of room, my garden is basically a courtyard with pots, thanks for the offer though.