To propagate Siberian irises, you can divide them into sections and replant them. You can divide them in early spring or late summer. 

When to divide 

  • Early spring: Divide when new growth appears
  • Late summer: Divide in August after the plant has bloomed

How to divide 

  1. Dig up the entire clump with a shovel or spade
  2. Remove dead roots and foliage
  3. Cut the clump into sections with a sharp knife
  4. Each section should have a good root system and several growing points
  5. Replant the divisions immediately

How to replant 

  • Plant the divisions at the same level they were growing
  • Cover the rhizomes with 1–2 inches of soil
  • Water regularly for the first 6–8 weeks

Why divide

Dividing Siberian irises ensures continued bloom. You can also share the divisions with friends and neighbors.