Rotten Window box
By Davidbrown
United Kingdom 
I have made a window box in the past, the stiffener supporting the front and back rots away - weakening the box. Could i flatten ends of copper pipe and use this instead of wood or would the copper affect the plants?
11 Mar, 2016
Well, the pipe is likely to add minute amounts of copper to the soil within, particularly if the container is in full sun and gets quite hot, but probably not enough to cause an issue. It might be safest to line the box so that the copper is not in direct contact with the soil or plant roots, because some plants are more sensitive than others to copper levels, so I'd use that soft polystyrene sheeting that often comes wrapped around delicate objects when they're shipped.
11 Mar, 2016