Since no knowledgeable person has posted, I'll take a guess that they're still establishing themselves, growing strong roots, & storing up energy before they gamble expending their energy on flowers.

Unless they're planted too deeply or in too much shade, I bet they'll bloom next year.

my gut reaction to greenery in favor of bloom is either:

lack of light ... which you have tried to remedy ...

of too much high nitro fert.. otherwise known as lawn fertilizer ...

did you fert at planting??? ... since??? ... and could the lawn fert be interfering ... as in the lawn guy keeps hitting the plants???

and finally.. maturity .. as noted above ... [which could be impacted by improper planting]

ken

Thanks to both of you for responding. Ken, we do not have a lawn so the lack of blooming can't be due to fertilizer. Back in the woods they definitely are in full time shade. In the front borders, they are in partial to light shade. Not much light, but some. I have toad lily, hosta,geranium and astilbe next to the iris and they all bloom - oh, and azalea too. But no iris cristata blooms. Frustrating as my research online shows that they should bloom where they are. Maybe they need more time. I may try transplanting another batch and putting them in a sunnier spot in the bed. One of these years I would LOVE to see a sea of little iris in the spring!