Evergreen architecture - Overgrown buildings and greener living

Nature and architecture have never been more intertwined. As more of the earth's surface is swallowed up by the built environment, architects are increasingly up to the task of integrating flora and greenery into their creations. There are many ways to express this : green roofs, living walls, indoor courtyards and entire facades filled with plants. But where these are posed as solutions there are yet more questions.
How does a skyscraper uphold the weight of hundreds of trees ? How do residents keep moss-covered walls alive ? Jungle Architecture explores this, and much more.