This is well within the realm of possibilities. While Christ was required to carry his own cross, this referred to the horizontal piece. The vertical piece is not mentioned and so nailing the cross to a vertical tree would be easy enough to do. The idea is fascinating on so many levels. Tree of Life, Olive tree symbolizing in OT and NT, 'cursed is he who hangs on a tree' Deut 21:22,23...good stuff.
This is well within the realm of possibilities. While Christ was required to carry his own cross, this referred to the horizontal piece. The vertical piece is not mentioned and so nailing the cross to a vertical tree would be easy enough to do. The idea is fascinating on so many levels. Tree of Life, Olive tree symbolizing in OT and NT, 'cursed is he who hangs on a tree' Deut 21:22,23...good stuff.