Fall is the perfect time to separate irises while the ground is becoming more cool and the growing season nears to an end. Irises are known for their gorgeous flowers. However, irises tend to spread and clump together, via rhizomes, leading to reduced blossoms each year. Therefore, they really benefiIt from periodic separation so beautiful blooms continue to emerge in the spring.
For large clumps, use a shovel and dig about 1 foot around the perimeter of the clump to account for the roots. With a hand trowel, you should be able to gather up the clump and shake off any excess dirt.
Now that we are disturbing the roots, it helps to trim the leaf fan back to allow the plant to direct its growing energy to the roots rather than support the full leaf fan.
You can gradually parse irises by using pruning tools or separate by hand. Select an individual rhizome with a central leaf fan for transplanting.
Once you have prepared your soil, place your newly divided irises just below the soil surface. Iris rhizomes need plenty of air, sunlight and a well-drained soil to establish itself and produce blooms for the following spring!