No need to cut the leaves, they will all die down for the winter. They are very hardy so I imagine they can stay in pots, though I would sink the pots at least partially in the ground and cover with leaves etc.

thank you chadinlg..i do have a spot that i can put them in the ground....i also have some pachysandra terminalis should i do the same with them or will they not make it through the winter??

Hey I'm just a California boy... but I imagine it would work for those too.

My understanding is that cold weather without snow cover is the worst thing for plants, so mulch them for protection. Some people call snow 'white mulch'...

I`m ukrainian boy, I newer cut the leaves of the japanese irises in fall, in the spring only.[quote]sink the pots at least partially in the ground and cover with leaves etc[/quote]
Yes, this so!