Check out Trachleospermum jasminoides - this is a lovely thing, with fragrant flowers in the summer. Don't attempt a trough for any climber though, not sufficient depth of soil - get a container that's preferably 2 feet deep and 10-12 inches wide as a minimum, more if you can manage it. Clematis will grow in tubs of this size or more, but not as well as in the ground, and you'd need to keep the pot shaded, as they like their roots in the shade and their heads in the sun.

Well thats Honesuckle out of the equation then, they hate root restriction and suffer from mildew more easily and lose leaves especially on the lower stems. Jasmine is probably the best as they can grow in pots for quite a few years (with a little tlc) for longer than most. J. beesianum or J. x stephanandrum are good ones. If you want scent, J. officinale is good with possibly the Scottish named clone 'Inverleith' amongst the best. J. o. 'Clotted Cream' is another goodun'.

Good call Bamboo.

Thanks a lot!

Bobo, Do the boards run parallel to the wall or do they butt up to it? I was just thinking that it you could lift a board up and replace it with a hole in it, a plant such as a Clematis may prefer the shade of the board.

Worth a try, Heron - thanks. If not the other responses have given me a few ideas. Once again thanks everyone.