Although on our annual green roof tour of Switzerland, we noticed this excellent green wall on the Sihl City complex in Zurich. Nothing complicated – just about five species of different climbers using a Jakob steel system. The wall is five years old and will confound them that say climbers take years to establish on a wall!
Whilst we there photographing the wall a few House Sparrows flew in and perch on the vegetation. Then they dived behind. Perhaps there are a few nests?