I have an evergreen clematis "clematis armandii" produces white scented flowers in spring and is quite fast growing, think it might suit!

I was about to recommend another white clematis, Dido - "avalanche", but I'm not sure about it's being either evergreen or scented. I'm only commenting, because I would quite like to read any ideas others may have.

I had a similar problem but bought some ceanothus and trained it up some willow trellis. Lovely blue flowers in spring and dark green foliage all through the year. It's not strictly a climber but if you train it daily in the first summer it will soon cover the area you need covered.

I can't find any pictures of a wall, hideous or otherwise, which have been posted recently. How tall and wide is the area of wall you want to cover, and does it get any sun, lots of sun, no sun, or partial sun?

Thanks for the clematis ideas. I had thought about clematis but was unsure of evergreens. Any idea how wide they would spread? Bamboo, my "wall" picture isn't recent. If you look at my pics you can't miss the awful grey breezeblock wall. It's about 12ft high and 18ft wide so I will need quite a few climbers to cover it.

And the sun or shade situation?

I have just come back from the garden centre and the Clematis "Avalanche" was there and it says it's an evergreen , it is gorgeous!! but my husband said not to get one yet until i was ready for it lol i was so tempted though!!

It's only rated as H3 for hardiness, Teddygirl - and its a scrambler, not a climber... still want it?

'Grey breezeblock wall'? What damage are you worrying may occur?

I'm not worrying about damage Smorgie hahaha, it's the back wall of next door's stables!! The owners have stipulated that I can grow climbers up it as long as they don't damage the wall. If it were left to me I'd knock the blooming thing down - it's awful.
Bamboo, the wall faces south and is pretty sheltered.

I did manage to find a shot of the hideous thing - I can see why you want to cover it. As that photo was a while back, I don't know whether you have a planting border in front of the wall or not, because a fair bit of cover can be achieved by planting free standing larger shrubs along there.
As for climbers, bear in mind that all will need something to climb up if they are not self clinging plants such as ivy, hydrangea petiolaris, schizophragma integrifolia or parthenocissus varieties. Strong, rigid trellis for Actinidia kolomitka, honeysuckle (Loniceras), wisteria, passiflora, Campsis radicans, Akebia quinata, Trachelospermum jasminoides, Jasmine nudiflorum and J. officinale, and clematis mesh for most clematis such as 'Polish Spirit' or C. alpina Frances Rivis, for instance. You should get permission to erect the supports from the owners of the wall though - or put in fence posts just in front of the wall and erect the trellis on those instead, covering the trellis with clematis mesh, if you plant them. Supports should be erected prior to planting, however you do it. Even if they allow you to fix trellis directly to the wall, it is best to use wood battens, so that there is a gap between the wall and the trellis to enable plants to twine around it. All the climbers mentioned will be fine in that situation, barring Hydrangea petiolaris, which prefers dappled shade. Note that Jasmine nudiflorum will need to be tied onto any support.

Thanks for that Bamboo. Very helpful and gives me something to think about. I have spaced 3 Photinia Red Robin along the width of the wall and about 4ft in front of it, also a couple of azaleas in between but other than that there is no border to speak of. I have googled the plants suggested and love the look of the wisteria ... I didn't realise that there was such a thing as an evergreen wisteria. I think that may be first on the shopping list.

Wisteria can take a long time to grow and even longer to flower, but, having said that, one that we planted 2 years ago has suddenly got the bit between its teeth and is growing like mad, covering one wall of the summerhouse. I didn't know you could get evergreen ones!

Erm, I didn't know there was an evergreen wisteria either - and in fact, there isn't.
The plant called evergreen wisteria (in USA and BC) is actually Millettia reticulata, and its only semi evergreen. Whether you can find it here is another matter - I've never seen it for sale, even on line. Said to be hardy in USDA Zones 7-10 - usually, when a plant is impossible to find here, its because they don't stand our winters though. Often its the combination of damp cold that they can't cope with, although I don't know about this one.

Sorry Bamboo, a slight misunderstanding. I'd like something evergreen on the wall (as in my original question), hence I thought your suggestions were for evergreens. I'll put a recent picture of the garden on(and wall). I still have a lot to do but every little plant helps :-)

Ah I see - yes, sorry, I concentrated much more on what kind of support you'd need depending on the plants you chose. The range of evergreen climbers which will provide good coverage on that wall is limited. Ivy will do it, but gets out of hand and may damage the wall. Trachelospermum Jasminiodes gives good coverage, but takes a while to get going.