I have a splendid old farmhouse on an island in Washington state. Sadly, attached to it is a good-sized and nothing-if-not-ordinary carport of far more recent vintage. While there's a part of me that wants to tear the carport down, the fact is I have a car and thus use it. What I do think is that one or more dripping vines would go a long way towards softening matters yet I am not interested in waiting years for Virginia creeper, say, to climb up and about. Thus do I wonder about emplacing large pots up top, or even have made a long cedar trough to skirt the edges of the flat roof. Has anyone experience with this kind of thing? MUST all vines' roots be in shade? Certainly is the roof exposed to all of the elements, very much including the sun.