Nick: It is a marginally good sign that the two trees that haven't leafed out still show green under the bark. Did you look at any new buds to see if they are still green? It is very unusual that they would take so long. How extensive was the pruning? The buds that would break on young trees are on the newest growth. There would be other latent buds that, if the tree still had functional roots, might break later. The problem is that roots can't really show sustained new growth without the carbohydrates produced by leaves. You might pull the tree out of the container to see if it is waterlogged or bone dry and if there seems to be much new root growth. Put it back in the container after inspection. The stone fruits (peaches, plums, cherries, apricots, etc.) are really sensitive to waterlogging. If that happened, it might also have shut the tree down. Finally, depending on where in Washington County you live, a very hard frost at just the wrong time for these particular plants might have damaged buds which would have turned brownish. All this is just speculation. Let me know what you find. Chip  <personal data hidden>   Chip Bubl OSU Extension Agent/Columbia County.<personal data hidden>.

Nick: Those pictures don't offer much hope but you really have nothing to lose by re-potting them. The lack of any fine roots is not normal and the tree can't function without them. The other problem is that these are grafted trees and you might get growth from below the graft but they would have rootstock characteristics which won't produce fruit of the type you were buying (rather small and not normal flavor at best)   I would contact the place you purchased these from and indicate that two of their trees did well and two didn't. They should offer you two new trees. Chip