Posted: 30/08/2015 at 11:24
Have a look at this article here on the RHS - https://www.rhs.org.uk/advice/profile?pid=467
I would suggest pyracantha which has woody stems so would support its own weight but can be tied in to a wire framework screwed to your posts and stretched across your fence panels so it hides the posts. If you plant several of them at regular intervals you can cut the leader at the top of the trellis and train all the side shoots along horizontally. Remove any shoots that grow out away from the fence and can't be bent in and tied to the framework.
It is evergreen, has spring blossom attractive to birds and insects and autumn berries attractive to birds. When mature it provides good shelter for birds and insects and a good backdrop for other plants.
I wouldn't go for a montana clem as they are very vigorous and need constant training to stop them getting top heavy and bare at the base. A viticella such as Etoile Violette will provide flowers all summer long from June to September but can be cut back in autumn once the foliage goes brown to reduce wind resistance. It then needs to be cut back to about 9" in March and given a very generous feed of clematis food to encourage all the new stems and flowers and occasional liquid tonics of tomato feed. Blue Angel is a good clem if you prefer lighter flowers but will take longer to get established and produce lots of stems. Huldine will spread to 6 metres if well trained and has lovely pale flowers with a bar on the reverse.
As FG says, bulk up your soil with loads of well rotted manure and/or garden compost before you plant anything.