> Or transplant shock?
I guess you didn't notice if growth had stalled before the first freeze? It's interesting that RENOWN didn't and it's the one moved from your garden to the pot. How long did it lay around before you put it in the pot? Buying RENOWN might not have given any answers. Not every transplanted iris has the 'dwindle' effect. Of 13 new acquisitions last year, only two did that - one AB and one TB. Of those I moved from one location in the yard to another, none had the main fan dwindle. Despite seeing a number of plants with the freeze effect, none of the transplants had any. Frankly I think moving delays growth enough that transplanting slows development down enough it often allows them to escape the freeze effect. That's based on my observation, primarily with ABs, that moving delays the bloom time by a week or so over their normal bloom among the other iris. Obviously that observation is limited to things already growing and then moved. I have no comparison for a new acquisition.
Texas Zone 7b, USA