A few months back a retaining wall at my parents house collapsed. Luckily no-one was hurt, but my dad decided this was an opportunity to rebuild it as a green wall. The structure of the wall includes large support beams and a steel-mesh, holding up sandbags filled with soil.
We started an ad-hoc planting programme, using mainly succulents and creepers from the garden. I am happy to say the plants have taken off and the wall is starting to look like it should, green!