Moving a Silver Birch (Betula Pendula)
 

Is it possible to dig up and relocate a four-year old Silver Birch? (well, planted out four years ago, was 5' tall when bought)

Planted it too close to the back fence... it's now about twelve feet high, but still quite skinny in the trunk.

If you think I could, how big an 'ole do I need to dig in order to avoid root damage?

Any comments welcome!