To filter the waste water of our workshop while using it for growing flowers or vegetables, we made a glasshouse against the wall of our barn. We used techniques as promoted by "De Twaalf Ambachten", such as lowering the glasshouse half way into the ground to collect in the cold season some stored warmth from deeper layers.

Under the cover of this glass house shallow trays filled with a mixture of shredded foam plastic and compost are attached to the brick wall of the barn, facing South. Our neighbour Paula had put a diversity of seeds into these shallow trays.

Yesterday I received my first feedback from nature: notwithstanding a glass cover mice found a way in and dug up and eat most of the planted seeds.
Trying to be smarter then mice, I used a lot of waste glass strips. I placed them close together with only a narrow slot between them for ventilation. The space offered under the glass cover should be high enough for the seeds to grow up some more. When then the glass strips are removed, Paula expects the plants will not to be appriciated by our mice anymore.
However such a protection is not in line with the more simplified setup for growing vegetables as described in the project idea Green Walls. According to this idea there is no need for a glass house. A plastic cover hung over the plant trays could give the neccesary protection. I doubt if this plasitc will also give protection against hungry mice. Yet this problem has to be solved.