Irises: Why didn\'t my irises bloom?, 1 by crabmeat

crabmeat wrote:
I have been growing purple German Irises for more than a decade. Nineteen months ago I divided them (I did it once before, about 6 years previously) in September, which is the right time to divide irises in our area (central Texas). I gave bags of the extra rhizomes to friends. None of the irises (mine or my friends) bloomed the following spring, which surprised me, since they had bloomed six months after division before. This year, my friends\' irises bloomed in March, but mine didn\'t bloom and show no signs of blooming. Over the last decade, they always bloomed from late March to early April at the latest. They are on a sunny hill (as before), they are healthy, they have excellent drainage, they were planted properly, they got the appropriate amount of natural fertilizer in December and yet, no blooms. We did have a cold snap in mid February, which isn\'t unusual. I don\'t understand why they didn\'t bloom. I wonder what I did wrong. Can anyone give me some tips to help them bloom next year? I\'m enclosing a photo of what it looks like when it\'s blooming.