I've sometimes thought that it would be nice if there was a hardy perennial cucumber or courgette - grown for those big bright golden flowers and luxuriant foliage. Well, this is probably about as close as I'll get. Neither the flowers nor the leaves are anywhere near as big but they have the same sort of cheerful vigour and can cover a trellis or 'unsightly object' (as the old gardening books always had it - an oil tank perhaps, or an abandoned car, or a slow-moving neighbour...) very quickly. Maximum hight seems to be about 8ft before it dies down for the winter.
In hotter climes it produces soft red fruits in late summer but not so far here.
Be aware too that the plant grows from tubers which are produced anew each year, usually some distance from the original plant. They're usually close to the surface if you want to control it or spread it about.
1L pots ~ £6