Our hotel in London had this beautiful living wall on the outside. It was quite interesting, we were a party of five people, and only me noticed it. How does that happen? It is so beautiful and unique. I am going to find out how difficult this is to do. Maybe succulents will work well, needing less water?
This link gives an easy way to this: http://www.plantsonwalls.com/
WikiHow says: A living wall is a vertical arrangement of plants and other organisms that naturally removes toxins and unhealthy contaminants from the air that we breathe. Living walls can be complete ecosystems or simpler configurations of plants that thrive in and help to decontaminate urban environments. Many living walls are indoors, but they can also be outdoors, such as on the exterior walls of buildings.