No blooms for 3 seasons on Siberian irises?

My Siberian irises refuse to bloom. I purchased them as large clumps from a seller at a local farm market. They've looked healthy, for the most part, but each of the three years I've had them I've had no blooms. Not a single one.

I did move them at the end of their first season with me (September) when I moved to a new home. So last year I figured perhaps they were sulking being first divided by the grower, then planted by me, then moved and planted again all in one season. This year I was hoping for blooms but all I seem to have is foliage once again and at least one of the three clumps appears to have gotten smaller and looks to have died out a bit in the center. Normally when a plant dies out in the center I'd say it's time to divide...but this clump is small to begin with.

These irises are planted a spot that gets between 4-6 hours of sun in slightly sandy loamy soil.

I'm not an iris officianado, and these are actually the only irises I have. I'm just hoping someone can help me figure out how to get them to LOOK like irises instead of just spiky grass. :(

Sandy loam is great for sibs, so you're good to go there. More sun would be better in your area.

If they are dying out in the middle they need to be divided. We just had another thread on a similar problem.

What's happening is when the seller divided them they took a good size piece off a clump. So that piece was already congested. That's why when you get siberians from a grower they will come in 3-6 fans normally. They are divided up so they will be blooming size the next year.

So, you're going to have to divide them again. Divide into six fans each and water them in with Miracle Gro when you plant them and keep them mulched, well watered for the rest of the year, and give them Miracle Gro a couple of times.

Good advice, Polly.

Thanks so much, Polly! I do have a sunnier spot that I could move them to; I just have to prep it (it's not dug yet, but I have the vision in my head.) I think I'll do that, and when I move them I'll divide them and keep them watered/fertilized as you suggested. Perhaps next year I'll have blooms. :)

I bet you will.