Posted: 17/06/2012 at 20:58
Clematis cirrhosa - 'freckles' and 'jingle bells' are evergreen and grow very quickly. I bought them as 2 inch seedlings at the beginning of last year and they are now romping upto 6ft high on trellis. Discribed as vigourous but not invasive, the first has white/marron flowers, the second - creamy/white.
Another one I bought last year - Solanum Glasnevin, keeps it's leaves over winter, might be semi evergreen though, you'd need to check, mine kept it's leaves last winter, grows very quickly, needs encouragement to bush out, I've been nipping it's shoots. Flowers May to September with tiny lilac flowers.
Lavatera Barnsley, mine kept it's leaves this year but again this could be semi evergreen, it was one I grew in a pot before planting out. Flowers June to September, with flowers that are white with a pink centre, I suspect very insect friendly.