Posted: 17/05/2015 at 21:10
I was sent some germinated astrantia seedling by another forum member last year which she had dug up from between gravel where they had germinated. She put them between damp kitchen paper, wrapped them with cling film and put them in an ordinary envelope in the post. They arrived a couple of days later and now are merrily growing in the back garden.
I know that they weren't tree seedlings but it could work the same. Perhaps you could experiment with sprouting some seeds and send them to someone you know to see how they get on.