Richard,
Moving iris in July, August they will be likely to bloom the next year. You don't need to move them in the spring when they are actively growing. In fact I would think they would be more likely to bloom if moved at the right time. Some small growers will dig in bloom when someone is there to look at the iris. I have heard good reports of next year bloom with that planting time too. The most important thing is to have the place ready to plant and get them right in. I should talk!
