One thing about osage saplings is the roots go to China, they have a huge taproot. Be careful digging them up so you don't break the tap root off and harm the sapling.
I had a bunch in gallon pots, some of them grew a taproot out the bottom of the pot and into the ground. I didn't know this when I picked up the pots and broke a few of the taproots off, these saplings died.