I have the same issue. Full sun, you mean they need it or not? Mine are in my sunniest bed...but that is not FULL sun by most measures.

Sorry.,. Those are the necessities. 6 hrs. full sun is recommended.

They have full sun and I don't over-water, but I also don't fertilize... Kind of let my plants fend for themselves :) and they're all pretty happy that way... Is fertilizing necessary for them to bloom at all?

Florananny, are there nearby tree roots? Very strange. Healthy foliage in sun with soil drying between waterings sounds good.

Had a front tree removed along with a mass of English ivy and I planted beardeds in the area. No bloom. Foliage and growth fine. I had not dug in a balanced low-nitrogen fertilizer. Duh. Salvias, marguerite, penstamon --- all did great but not the iris nor 2 rose bushes. I've begun fertilizing. Part of the problem here may also be our drought.

I have had Zebra Night for about 10 years that has never bloomed. Full sun, happy iris & other plants all around it, but nary a bloom. Hasn't multiplied either. Last year I received some of both white variegated & the yellow variegated iris, they look great & developed some, but didn't bloom this spring. We'll see what happens next year, but the foliage is interesting in itself.

Irisgal, it is very odd... No tree roots to speak of. Dug out and planted this bed about 6 years ago, irises went in about a year after. Bloomed first season then never again, 'though plants have multiplied [modestly] and the leaves seem healthy...

When someone posts about their regular-leaved iris not blooming often it is mentioned that they might be over crowded and need to be divided. . Since we grow these iris for their leaves, maybe we are loathe to be dividing and they don't bloom as much? Just a thought.