We have an old wall, waist height, between us and our neighbour. Waist height to head height is trellis, and neighbour has a seating area right against the trellis which makes me feel really exposed. It gets sun first thing till 3ish, and the key is rapid growth. I can put troughs on the top of the wall against the trellis (the wall is wide) but don't know what to put in them. Would some morning glory seeds work? Help!