Since my back garden is south facing it gets lots of sun but the back wall is obvisously north facing - it's about 3ft high and my garden is pretty exposed and being in Scotland we do get some wild and cold days! SO.... I'm looking for some decent sized shrubs to plant on this wall, would like them to ideally be flowering, can rhododendron be grown in shade like this?

Hi blinky, yes rhododendron would be fine, as would any other woodland plants.
Many woodland plants like Rhododendron etc require an acid soil, so just check that this is what you have, look around your area and if such plants can be seen growing then you will be fine. Here are a few more that would be suitable.
Azalea, Peiris, Aucuba, Skimmia, Camellia, Berberis, Eleagnus, Ilex, Mahonia etc. etc. I'd personally choose plants for their foliage as you have this year round, most flower but think of flowers as a bonus, you cant rely on flowers alone but the foliage will give you pleasure all the time. Also, think about texture of foliage as well as colour.
regards Lannerman.

Scratch that idea...... After talking things through we are going to plant a load of perrenials, picked up some yesterday that flower in full or part shade. I will move the Rhode that I currently have into some nice big tubs and stick them on my new decking which is going down in a couple of weeks and will be south facing.