As anxious as we all are to see a new Iris bloom for the first time -- I would be unhappy if a newly planted rhizome bloomed the same year. By the time that you get your rhizomes from a dealer, they are just coming out of dormancy -- and SHOULD get busy growing new roots, settling into their new spot, and creating increases. The amount of energy required to produce a bloom could sabotage all of that, and the very survival of that rhizome. FWIW.
Edited to add: what a beautiful order you placed!!!
