I've collected quite a few Ponderosa, and have about an 80% survival rate. Personally, I think the choice of which tree to collect has had the most effect on my success.
When I bring a collected tree home, I try to remove as much of the native soil as will come off easily. I don't worry about getting all of it. Then I pot up in something very freely draining, and make sure the tree is secure in the pot. These trees then sit on a pea gravel bed on the north side of the house for a year, and get buried in the pea gravel over the winter. Usually when I pull them out of the gravel the next spring I can see roots growing out of the pot. At that point, I pull them out of the pot, remove most of the rest of the native soil, and repot as before.
If this tree were mine, I would gently pull it and examine the roots. If they are growing well, I would try to remove most or all of the native soil. If the roots are iffy, I would only remove the native soil that comes off rather easily.
Brian
