Ken, at our last home we had a fabulous native dogwood with heavy branches that draped to the ground. The flowers were very large for a native and it seemed like every seed that dropped under that canopy of branches sprouted. All our friends wanted one. We learned that we had to take a good bit of the native soil with each one we dug. If the soil fell off the roots and we planted it in topsoil or potting mix it was sure to die. As long as we were able to keep as much as possible of the soil the seed had sprouted in around the roots, they transplanted just fine. There must have been some beneficial microbe under the parent tree that was necessary for growth and development.