John, I heard that potting soil is made for pots and garden soil was made for ground planting. It seems that I read that the potting was not as moist....not sure about that. I used the potting soil when I got the fans...they've grown substantially and needed to be placed in the ground.
Charley, I sure hope the potting soil is ok. He did add the alfalfa pellets and milorganite to the hole before planting, so I would hate to dig them back up.
