Nature does not forbid the planting of a tree in the sky.<quoted text>
So, since nature does not FORBID the planting of a tree in the sky go right ahead and plant one.
A tree cannot be planted in the sky since the right conditions for germination of the seed especially soil does not exist in the atmosphere. Perhaps, a hydroponics experiment could succeed in the sky if a seed could be anchored in a pocket of aerial water vapor.
Nature cannot forbid or condone anything since it works on the basis of causation.