How to divide iris rhizomes

in Home : Projects: Propagating

You will need

  • Irises
  • Garden fork
  • Sharp knife
  • Trowel
Do it: July - August
Takes just: 30 minutes

Project categories

Overview

Irises can become congested over time, which tends to inhibit flowering. This can be remedied by lifting and dividing their rhizomes to give them a little more space. Wait until flowering is over before dividing the iris clump, discarding any old, woody rhizomes and replanting only young, healthy plants into freshly-prepared soil.

How to do it

Irises being dug up

1Use a fork to dig up a congested clump of irises. Ease the plants from the soil, taking care not to spike the rhizomes.

Pulling apart iris rhizomes

2Pull the congested rhizomes apart by hand, or cut them with a knife. Choose healthy pieces with leaves and discard old, woody sections.

Trimming the leaves of an iris

3Newly-planted rhizomes are vulnerable to wind rock, so it's a good idea to reduce the leaves by half. Use a sharp knife to trim them.

Replanting irises

4Replant healthy rhizomes about 12cm apart with the leaves facing towards the sun. Make a shallow hole and half bury the rhizome, giving it a firm push to bed it in - they like to bake in the sun, so don't bury them too deep.

Adam's tip

It's a good idea to lift and divide clumps of irises every three years.

Discuss this project

Talkback: How to divide iris rhizomes
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molene 24/11/2011 at 15:28

I have some Iris's that I planted last year. They didn't flower then but I thought they would this year. Still no luck. What am I doing wrong?

luise_gregory 24/11/2011 at 15:28

Help! I am getting addicted to your website! Thank you so much for all your help and advice. I am a new gardener and you are my bible.
Question: Once Irises have stopped flowering. Can I cut off the flowering stem immediately? Do I leave it as with daffodils?
Thanks in advance for your reply.