I would think they would be fine left in containers.

I bought some this season, in containers, and may just plunge the whole pot into a temporary spot, if I don't get a permanent spot prepared for them this season.

All of a sudden I have too many peonies it seems...or is that even possible?

Sue

Your peonies will be just fine, although mid-summer isn't the best time to move them, I had to do that too. Just dig as big of root ball that you can and put them in large pots, and keep them well watered. Mine have been in pots for a little over 2 years and they bloomed happily this year. We, too, are renting and my peonies are going to stay in pots until we finally buy a place.

I think the important thing is, as terry says, to have as big a root ball as possible-the more of their "home soil" you can take along, the better. Also, if they are going to be moved in the back of a truck or something where they are exposed to the air, wrap the whole plant and pot in an old sheet or something to protect from the wind-but not plastic. Keep them shaded and well watered and they should do fine.