Ever since I planted these Siberian irises a few years ago, there have been no blooms and many of the leaves are crimped. See photo. What causes this & how can I fix it?

I've never noticed that, on beardless irises before, but on the bearded, I usually blame the weather......a sudden warm spell accelerates the growth, and the new "inside " leaf on the fan grows "faster" than the "older" outside leaf can open up, to allow it to emerge.
How is your soil ph ? Beardless like it well to the acid side, and soil that is 'too sweet' (too much lime) will retard bloom, and, even kill the plants.

Looks like Louisiana iris leaves to me? Mine do this too. The leaves straighten out as they grow.

I've had some of my Sibs do the same thing, but I don't know what causes it. I suspect they were too dry where I grew them and now that I've moved and taken the Sibs with me, I hope to find out. We did have a lot of late frosts this year, but they have just emerged and I haven't seen any 'crimping' yet. I'll try to remember to keep an eye on them.

Many of my tall bearded irises do this in weather that has warmed, then turned cold again. I noticed a lot this year, but they otherwise look healthy and no "stuck leaves" this year. I believe the term is pineappling.

I've just checked on mine and they are blooming with no sign of 'crimping', so no conclusion from that I'm afraid.

@Kmclaugh4

I suspect you were asking as much about the not-blooming as about the crimping. There is a short how-to on this site at The Irises Database Go down five items. Some possibilities, not enough sun, poor soil, planted too deep and not enough water. When I had siberians I always gave extra water for several weeks before bloom. Good luck

I agree with Tienito that that looks more like the foliage of Louisiana irises. And my Louisianas do that every spring. My Siberians never do it, and they have much narrower leaves.

As for" no blooms," consider that if these really are Louisianas instead of Siberians,

a) they need more water, especially during summer droughts, and
b) the bloom scapes of Louisianas tend to lie lower (procumbent), with blooms sometimes unfortinately hidden in the foliage. In addition, the bloom scapes are often camoflaged with leaves along their length. Try to identify the bloom stalks early, and stake them.

Give it plenty of water this summer and hopefully it will reward you with bloom next year. Louisianas come from the swamp lands of the South, so while they can tolerate freezes, they really hate summer drought. I have mine planted where the neighbor's sump pump drains onto my property. If you try to locate yours to a moister spot, wait until September or October to dig it up, and don't let the roots dry out. Unlike German iris, they really hate being dug up in June, July, or August. If you planted it during one of those months last year, that may be another reason it did not bloom this year.

As for" no blooms," consider that if these really are Louisianas instead of Siberians,

a) they need more water, especially during summer droughts, and
b) the bloom scapes of Louisianas tend to lie lower (procumbent), with blooms sometimes unfortinately hidden in the foliage. In addition, the bloom scapes are often camoflaged with leaves along their length. Try to identify the bloom stalks early, and stake them.

Give it plenty of water this summer and hopefully it will reward you with bloom next year. Louisianas come from the swamp lands of the South, so while they can tolerate freezes, they really hate summer drought. I have mine planted where the neighbor's sump pump drains onto my property. If you try to locate yours to a moister spot, wait until September or October to dig it up, and don't let the roots dry out. Unlike German iris, they really hate being dug up in June, July, or August. If you planted it during one of those months last year, that may be another reason it did not bloom this year.
P. S. I think I actually see several bloom scapes in your photo. Loiusianas bloom later than the Siberians, and, as I said the scapes tend to be camoflaged by more leaves. You wrote this May 16, and I am betting you've had some blooms by now. Let us know.