In Rawlings Conservatory they have a rock wool wall with a drip line that they use to grow tropical, bromeliad, ferns, creeping fig and some other plants. The whole end wall is a large growing bed. They did have some issues with water getting behind the wall and had to tear it down and redo it. They have metal grates over the whole wall with the rock wool behind it and I think there is sphagnum moss tucked in places between the rock wool and the metal grate.
Can't believe I don't have better pictures of this wall.
