Take into account that not all of our bloom seasons are the same. My irises are finished before some other areas start their spring bloom. I always divide and replant in June as my irises finish in May.
I have to plant the new ones that come later from generous iris friends whose gardens do not finish until much later than mine and from vendors who do not ship until late July and into September. A lot of these bloom first year so it sometimes depends on the care they received from the gardens they are coming from.
