I would think that an extraction from a wall would probably survive. Be aware that these trees sucker in long runs if planted in the ground, grow and get pruned. They defend survival by suckering vigorously and maybe annoying neighbours. I like to feel happy over the idea of a Sumach imprisoned in a pot! Worth a try but I would maybe choose a pretty Acer.

Thank yo SO much,having moved inland,I now only have a decking area(neighbours x 2 each have deck!)and I desperately miss my garden and stags head tree.I have a small courtyard with stairs leading up to the deck.I thought if I got a vast container the tree could settle happily into it and with lots of tlc would reward me by
taking root!I would definitely find a home for it when it was starting to look stressed(in a friends field!!)
Can you recommend an acer?that is a brilliant idea
many thanks

I'm not an Acer expert but I did know someone who had a lot of these in large pots ......like huge Bonsai. They looked fabulous.....but I guess there was a lot of expertise to growing so many that way. I understand they needed refurbishing every 3-4 years to keep them pristine and happy....but then she was a perfectionnista. Try Google imaging Acers and take your pick or go to A in the alphabet at the bottom left of this screen.