Question on Vertical Wall Gardening...

I was wondering if anyone has ever seen or heard of someone trying to grow plants using vertical wall gardening? I've been trying to find more about it and a lot of what I've seen has been really interesting. Part of my question is "what types of plants can be grown there?".

It looks like a lot of the plants I've seen people use are forbs or herbs but I was wondering if you could do small shrubs or grasses (like a cereal grain?). Does anyone know anything about this subject who could help me understand it better?

If your referring to what i think you are then , any above ground plants that are capable of hydroponics/aquaponics, and if using a wicking system can also grow root crops, i think the easiest way of answering your question is by saying " if you have a system that supports a 4 inch root ball , then any plants that grow with a 4 inch root ball" in essence design a system according to the plants you want to grow
If it's one like in this Video then use hydrotons or something that doesnt decompose, as slumpage will kill the plants...