I received some Iris bulbs from my mother-in-law last year. I had never had Iris in my garden before. I planted the bulbs and they grew and bloomed very nicely, but, the foliage never died back. I waited all fall and winter for the right time to cut them back to the ground like other bulbs but the leaves stayed nice and green. I would like to be able to cut the foliage back to the ground to control the size. When should I cut these back to the ground?
You're confusion lies in the fact that Iris are not considered "spring bulbs". Iris grow new foliage every year and blooms in late spring to early summer. Many Iris will look kind of ratty in mid-late summer and that (August) is the right time to cut off damaged leaves if you wish, and dig and divide to control the size of the clump. Each old flower stem may be flanked by two or three new shoots at that time.
Ah, I notice you're in Texas--I guess your Iris don't get the cold we do and have as much of a yearly cycle. Without researching, I'm still guessing you would divide them in the month or two after bloom, say in August, and keep only the best looking pieces to replant the amount you like to keep. Discard the older parts of the rhizome that have few or no leaves and roots.
I hope this makes sense to you! I'm pretty sure there are some Iris care articles in Dave's if you wish to "search articles" for Iris. Good luck.