Treating railway sleepers
We used new railway sleepers (which we assume were weather treated in some way) to create retaining walls about 5 years ago. Where plants trailed over the top of them, and created more moisture, they have started to disintegrate. We need to seal them on the end with some form of preservative. Everything we have seen at the DIY store has colour/stain, which we don't want. Would Linseed Oil work? If it is pure Linseed Oil, with no other nasties added, would this be OK to use near plants/veg? Any other suggestions welcome.