I do not have as many irises as most people on this forum and most of them are fairly new, so I'll only post 5:
Not the most fancy iris around, but for vigor and overall toughness even in less than ideal situations, it is unbeatable. Plus, I like historics and this is about as historic as it gets!
Another (much younger) historic. This is a first year clump - need I say more??
Classic spageager, which grows very well for me and blooms every year. A personal favorite!
Darn cute, very early, grows like a weed and should do well in your zone. Other MDBs do well for me too.
Not the fastest grower, but a reliable, heavy bloomer with great substance and a deep, rich velvety colour, which has to be seen in 'person' to be fully appreciated. If I could grow only one iris this would be on my short list!
Generally, SDBs and IBs are more vigorous here than TBs.
