You can dig them immediately after bloom. In my very short season climate, I regularly dig irises as soon as the last blooms have faded. The much more critical issue is getting them replanted at least 6 weeks before your first frost this fall.

Laurie

You can successfully dig them up and replant anytime.The trouble is they need 6 weeks after bloomtime to make food for next year. ...so if you dig them up right after bloom they may not reward you with a bloom next spring.

Thanks for the advice from both of you. We appreciate it.