I´ve read your blog with great interest and I have some questions on the construction of a green wall meant for the outdoor. As far as I can understand there is first a layer of treated wood or pvc, attached to that is a mesh of stainless steel and the comes the fabric. And here is my question. I´ve been looking at the MRM, but to me it doesn´t seem thick enough for cutting and putting in the plants? How thick is it? And does it only need one layer? Does the cutting of the holes go the whole way through?
Also when the plants are out into the holes, are the roots then cleaned for dirt?
This was just some practical wondering that I hope you may be able to help me with.
Here are the answers to your questions Sophie:
1. The first layer is the frame. Usually that's made of aluminum or wood. Then there's a waterproof layer of plastic. Lately I have been using recycled corrugated polyethylene sheeting; 2 sheets 6mm thick layered to make 12mm.
2. Click here to see the MRM that I use. It is 3/16" thick and in my experience has been thick enough. I have seen some Blanc walls that have used an even thinner material. The material is stapled to to the plastic in two layers. The cuts for pockets are only made to the first layer.
3. The dirt from the pot is left around the roots.
Because you are making a wall outside you should also consider adding a plastic woven or pierced layer behind and in between you MRM sheets. See this post for more info.