How do I Replant Iris Bulbs?

Iris bulbs are actually called rhizomes.

Iris bulbs aren't true bulbs. Instead, they are swollen root sections called rhizomes. These rhizomes hold nutrients for the iris much as bulbs do for other flowers. Whether you are digging and replanting the iris bulbs in a new bed or replanting after dividing an overgrown iris plant, doing so properly ensures the roots suffer little damage so the iris can return to full health the following year. Dig and replant irises two months after they finish blooming, as this gives the foliage enough time to replenish the nutrients in the roots.

Things You'll Need

• Compost
• Knife

Instructions

1. Spread 2 inches of compost over a well-drained, full-sun garden bed. Work the compost into the top 12 to 18 inches of soil where it supplies extra drainage and some soil nutrients.

2. Inspect each iris bulb before replanting. Cut off any soft or shriveled areas of each root with a sharp knife, saving only the healthy roots for replanting.

3. Plant the iris in a 6-inch deep hole. Place the bulb so the roots are on the bottom. Spread the roots out gently in the hole.

4. Add soil under the iris bulb until the top of the bulb sits just beneath the soil surface. Fill the hole in around the bulb and lightly firm it with your hands.

5. Water the planting area until the soil is moist to a 6-inch depth.

Tips & Warnings

• Cut back the foliage on irises before digging and replanting. Trim the foliage so it is no more than 6 inches tall.

• Divide the roots before replanting. Cut apart each root so it has at least one fan of leaves attached to it.

• Do not over-water irises. The roots rot in overly wet soil or standing water.

References

• University of Illinois Extension: Time to Divide Iris
• University of Rhode Island Extension: Iris Culture