Ivy's fine, nice to see it used. Ideally, as with all climbers (although ivy's tougher than most), it'll want a cool root run, so a foot deep or so, but the breadth and length might make up for an lack of depth. Although north facing, some clematis will also survive there, especially some of the smaller ones, like 'Bijou', a herbaceous variety, or an early flowering one, like 'Early Sensation'. Use a soil based compost

And I love the first line of the question. I was tempted to tease!

Thanks Worthy, it took me a while but I did laugh when I saw what you meant! Thanks for the advice. I may try an idea I read about with Dentata Variegata with Winter Jasmine growing through.I will also look up the 2 c
clematis you mention.

Depending on what wood the planter is made of and how its been treated it might be a god idea to line it with plastic to help prevent it rotting too quickly? You'll need drainage holes in both the plastic and the planter.
Dentata is pretty but bear in mind it can reach 4 - 8 metres eventually, so it depends on how long and strong your fence is. there are lots of smaller ones that are just as attractive. (You can get an idea of the range on google if you put in hedera varieties images. Unfortunately they aren't labelled.

Thanks, yes I intend to line with plastic, or rather hubby does. Will do some more research before planting up as now weather is so hot everything newly planted needs careful looking after and we are having to go away for a few days pretty regularly at the moment so do not want to loose any new plantings.Thanks for advice.