If you could mount some small eye bolts in the stones near the top to hang strings or wire from, you could have almost any climber/vine. Pole beans, sweet potatoes, cucurbits, climbing roses, or clematis come to mind.
What is your main objective - beauty, usefulness, or the bees? Do you prefer annual or perennial?
Liar, liar, pants on fire! refreshing plug:
Switching from electric heat to a rocket mass heater reduces your carbon footprint as much as parking 7 cars
