possibly. Are they crowded?

We had a LOT of late snowstorms and freezes here in the Upper Midwest this spring. They caused a tremendous amount of plant stress and diminished bloom substantially in my iris beds. If your reduced bloom is weather-related, there's nothing you can do about it. There are, however, a number of other factors that can negatively impact bloom, as well. You can find many of them listed and discussed in the FAQs (link at top of forum page).

Laurie