With their showy spring flowers, bearded iris is a mainstay in many gardens. They are generally low maintenance plants season after season, but over time they can become crowded and they stop producing as many blooms. That’s an indication they need to be divided. The time to divide iris is after they’ve bloomed, usually late June or early July. If your iris aren’t blooming like they used to or they’ve stopped blooming at all, it’s a sign they are over-crowded and it’s time to dig them up and divide them.
Once you’ve got the clump of iris out of the ground, you’ll be able to see the rhizomes clearly.
You’ll want to remove any old or diseased rhizomes. You can remove these and divide the clump with a knife or by breaking off each root with your hand.