High raised planting boxes from scaffold boards
I'm thinking of making some high raised planting boxes from scaffold boards. These would be 3 or 4 scaffold board widths high, reinforced at corners and a mid point by 3inx3in stakes that would also stake them into the ground. The bottom and top would be open. These are higher than most I've seen online (and only a foot and a half wide).
A) will that and a few other pinning together bits be enough to hold back damp earth?
what should I line the inside of these boxes with? I want to stop damp getting to and rotting the wood. Heavy plastic? Or does it need to be breathable? If so, any recommendations?
C) any other concerns I should be aware of?
Any advice appreciated.