Posted: 29/03/2014 at 17:09
Is the wall just plain brick, or rendered and painted? How thick is the wall; some friends in Wales years ago planted on top of a wall, in troughs and it worked well; you could make sure that the troughs were really secure. I would recommend for something fast growing; Nasturtiums. Also you could plant a variegated ivy which of course would be evergreen. The other option, which I know as a mural painter is that if you painted a mural, it tends not to attract graffitti. I believe, though that you have to get planning permission.