A friend of mine ask me why her iris no longer blooms. It's only a few (2-3) years old and bloomed the first year but, hasn't bloomed since. Any ideas why?
When she bought it the flower was already formed in the rhizome. That was the 1st year bloom.
If it is a tall bearded, zone 4 is not as friendly a climate as it is to dwarf beardeds.
The growing season is short so good soil, good drainage, & full sun are mandatory. Has she planted it with the top of the rhizome exposed?
Have any babies been produced? If so there's a chance another year of healthly growth will produce a flower in the rhizome. Tell her to not trim off green leaves when they begin to flop in summer.
The last resort is to find TB's that have proved they can take zone 4 winters. Does she know its name or who hybridized it?
I'll have to ask her what type of iris it is and get back to you.
I'm wondering how many iris rhizomes she planted and how close together she planted them. If she planted them really close together, it could even be that they are too cworded to grow to blooming size.
There really are numerous reasons why they might not be blooming.
There is a good answer in the FAQ here. I have no bloom on my bearded irises. Why are they not blooming?