How to Harvest & Store Iris Rhizomes

Iris rhizomes require harvesting and dividing every three to five years for the optimum number of blooms in the fall. Evidence that your irises need dividing is heavy, thick growth which looks cluttered. Divide the rhizomes in the early fall and save them for replanting in the late fall or next spring. Most irises can withstand very cold winters, such as those in North Dakota, according to Ron Smith, horticulturalist with the North Dakota State University Extension Office.

Shears
Garden spade
Sulfur dust (optional)
Peat moss
Resealable container

Instructions

- 1
  Cut off the top two-thirds of the irises.
- 2
  Dig out the entire iris plant with a garden spade.
- 3
  Sever the rhizome with the spade so that there are several smaller rhizomes, each with its own emerging growth of leaves.
- 4
  Lightly coat the rhizome with sulfur dust to prevent insect infestation.
- 5
  Fill a container with peat moss and bury the rhizomes inside the peat.
- 6
  Store the container in a cool basement or the refrigerator, where the temperature will maintain a steady 35 degrees Fahrenheit. Keep the rhizomes away from other fruits and vegetables in storage to prevent the ethylene gas they emit from hastening decay of the iris rhizome.
- 7
  Replant your irises in the fall before the ground freezes.

Gladiolus Bulb Information

Do Easter Lilies Like Sun or Shade?

Bulbs