Could it be the waco weather this spring? It has been a cool spring here.

Maybe more fertilizer

Don't know your soil but I'm inclined to think fertilizer too.

Iris need full sun. Over fertilizing causes lots of leaves and few flowers. To much shade also reduces flowering. It is cooler than normal here and mine are blooming now and They were all dug and moved last fall.

You may need to dig them even if the foliage isn't in big clumps. The rhizomes may have crowded more than you expect, especially since you have had good bloom in the past. Four or five years is a pretty long time for iris to be undisturbed. I would at least check out a few of them.
kay

Thanks everyone for your imput about my iris.
here is the picture.
Pat

{{gwi:1027181}}

I can see that you have mulched them! They dont like to much mulch. They like the rhizomes out of the ground just a little. Did you put it down lately? Or has it been there all along? Just an observation!

I did put down a thin layer of pine needles this spring after useing preen for crabgrass.

I don't know how well irises handle Preen. They are extremely sensitive to Roundup, and even a few molecules in the air seem to have a negative effect on the blooms. I wonder if Preen is the problem?
Renee

have you ever fertilized them??

they look excessively thin and tall to me ... too much nitro???? ... or lack of full sun ... they are 'reaching'

i grow in mineral sand.. full sun .... NEVER fert .. barely water beyond that given by the sky .. and thy bloom great ...

and i use roundup around them.. and know of no adverse effect .. hmmm ...

its all contrary to what you all suggest.. whats that all about .???

ken

ps: my problem seems to be borers ...