Division and Transplanting (Resetting) of Bearded Iris

The bearded iris is a popular perennial flower in Nebraska gardens. When growing in its favored sunny, well-drained garden location, most varieties will require division and resetting after 3-4 years. The need for resetting is best signaled by a diminished number of blooms, or no blooms at all. Rhizomes are typically reset 6-8 weeks after the completion of blooming, which translates to late summer or early fall. This timing allows some recovery time after blooming and also before the fall and winter dormancy period.

Management/Methods

• Tools
  • Garden pruning shears
  • Garden fork
  • Sharp spade or, preferably, a sharp knife
• Method
  • After the flower stalk has finished blooming, use a garden pruner to remove the flower stalk near its base
  • Remove any dried, yellow leaves or leaves exhibiting insect damage.
  • If division and resetting is desired, use the garden fork to gently lift the rhizome or clump of rhizomes out of the soil
  • Remove any dirt from the rhizomes and inspect for iris borer damage or rot. This is most easily recognized as soft spots on the rhizomes that yield to pressure. Damaged rhizomes should be removed and thrown away – they should not be composted
  • Rhizomes best suited to resetting are those found near the outside edges of the lifted clumps. The original, or ‘mother’, rhizomes near the center of the clump will not flower again and can be cut out and thrown away. Choose rhizomes having 1-2 leaf fans and healthy white roots.
  • Use the garden shears to cut the remaining leaves so that approximately 4-6” remains. Trim the root length to about 2”. Trimming the leaves keeps the rhizome from becoming top heavy and lifting out of the soil before the roots re-establish themselves and are able to hold the plant in place.
  • Place the rhizome on a mound of soil in the planting hole, spreading out the roots evenly around the mound. Cover the rhizome will soil so that the top of the rhizome is partially exposed.
  • Water the rhizome(s) well once per week as the reset iris acclimates to its new location.