AFTER the iris is done blooming it can be trimmed, transplanted and treated. This can be done from the time they are done blooming until fall frost. Sooner is better. When you dig them out cut the tops about 6-8 inches tall in an inverted V. Cut all the old dead, decaying & bug eaten parts off the rhizomes. Soak them in a bleach/water solution to kill any harmful critters riding along. Then replant however many you want to wherever you want to put them. Plant with the rhizome buried in the ground, but not above the white lines above the rhizomes.