I ordered a pjm from a local nursery and was told it would probably arrive later in the fall. I know fall is a good planting time, but at what point would I tell the nursery "thanks, but no thanks....it's too late in the season"?

Also:

I have a spring-planted pjm that's thriving, but the trunk is loose in relation to the root ball--almost like a tooth. Is this a cause for concern?

P.S. Thanks much rhodyman. I dug the aforementioned pjm up and it was doing well. However, one of my cunningham's whites had a rootball that was dry but for the outermost layer. The potting soil was like sawdust. No wonder it fell to drooping constantly. I hope it becomes more optimistic now.