This pretty shrub is a leycesteria formosa. I planted one in my garden a couple of years ago and it is absolutely stunning. Enjoy !

Spreads a bit and self seed around, but it is easy to control.

Thanks Scotter. It has turned up uninvited behind a shed. Its 5ft tall now so must have been there a while.

I have never had any success in getting it to grow from seed. :o(

They do grow rather quickly, but if it gets too tall you can easily prune it in spring without any detriment. It will bush up rather than taking off and getting leggy. I must admit I have never had self-sets.