So the hop wintered over very well. very very well. All i did was cover it in a foot of mulch. So I guess that is adequate frost protection in pittsburgh.
For spring I just dumped the pot cut the thick coiling rhizomes and gave it fresh soil to work on. It had pretty much filled the pot with roots.
The dumping process was a challange. I was trying to lift it and found that it was very heavy. The reason was that the four small drain holes in the pot had huge roots growing through them anchoring the pot to the ground.
So when I say hops can grow in pots I guess I mean they can but try their best to get out. here are the shoots comming up in force for the spring: