I love your idea and use an evergreen jasmine behind my own wall fountain. There are many types of jasmine and you do not mention where you garden but in the Pacific Northwest where I live the evergreen Jasmine polyanthum is hardy in zones 5-9 and bears fragrant white flower clusters in summer. I grow mine in a protected corner of a porch so it is evergreen all year and easy to clip and train. This jasmine does great in a pot and is drought resistant and blooms in sun or shade. Another option would be the variegated or white and green leaved ivy. There are many different types and these have smaller leaves than the invasive English ivy and are easier to control but very hardy. Good luck and Keep growing, Marianne Binetti