How to Divide Iris Plants


The word iris means "rainbow". True to that, iris bulbs produce a rainbow of colorful flowers on tall stalks that are excellent for cutting and enjoying in a vase indoors as well as in your garden along a fence as a background planting. There are over 200 varieties of iris. Irises spread by sending out stems underground. These are the rhizomes that you can cut apart and plant separately to create additional plants in your garden and share with others. When your iris bed gets crowded with plants, it is time to separate them.

Step 1

Divide iris plants in August or September after they finish blooming. Loosen the soil around a clump of plants with a shovel or fork and separate the rhizomes with a sharp knife.

Step 2

Trim the roots and remove any diseased or unhealthy-looking areas from each separated rhizome. Cut back the top leaves to 4-6 inches, leaving green growth to feed the new plant for future blooms.

Step 3

Prepare a shallow planting hole for each plant. Plant the individual rhizomes in holes 8 inches apart. Cover them with loose soil just to the base of the rhizome.

Step 4

Water the new plants and place a shallow covering of mulch on top, being careful not to cover the base of the rhizome. They will establish roots and produce foliage and maybe flowers in the spring. It may take another year for the new iris plants to bloom.

Tips and Warnings

  • If your iris do not bloom they are probably crowded and ready to be divided, planted too deeply, or overfertilized.

Things You'll Need

  • Iris plants crowded in a planting bed
  • Garden shovel or fork
  • Sharp knife
  • Garden shears
  • Planting soil
  • Mulch


  • Guide to Dividing Iris Plants
  • Iris
  • Dividing Iris

Who Can Help

  • How to Divide Bearded Iris
  • How to Plant and Spilt Iris Bulbs
Keywords: iris plants, dividing bulbs, propogating iris, planting bulbs

About this Author

Kathleen Sonntag lives in Carmel, California, where she is a writer, teacher and editor. She is a Master Gardener and writes articles for gardening publications. Sonntag has written and edited reading test passages and has edited children's books, cookbooks and memoirs. Her articles appear on Sonntag holds a Bachelor of Arts from University of California, Berkeley.