How to Divide Bearded Iris Rhizomes

By: Garden Gate staff

Safely and successfully divide your rhizomes in a few simple steps.

If you’ve noticed your bearded irises are losing their impact in the garden, don’t be dismayed: They can be revived quite easily with some simple division. Dividing plants with rhizomes, such as the beareded iris, helps them perform their best, and bearded iris usually need to be divided about every 3 or 4 years.

Know when to divide the rhizomes

If you’re wondering if now is the time to divide your rhizomes, look for these cues:

The plant is flowering less
The center seems to have died out and old rhizomes may even been seen emerging from the soil
The fans, or foliage, on the outside of the plant are beginning to flop

How to divide bearded iris and other plants with rhizomes

Dividing rhizomes can make such a difference in the health and beauty of your bearded irises. So let’s keep it as simple as possible, and it won’t be difficult to incorporate into your gardening routine. You’ll need pruners, a shovel and a hose. The best time to divide rhizomes is usually sometime in the summer when they are partially dormant.

Watch the video above or click through the slideshow below for more details about each step, and then head to the garden ready to get your irises back to what they once were!

You Might Also Like:
Troubleshooting your bearded irises
Helpful how-to gardening videos
How to divide 45+ favorite perennials
3 simple ways to divide plants
How to divide plants with dead centers

| 1 of 5

Dig up rhizomes

Carefully expose the roots of the rhizomes starting at the outer edge of the plant and gently lift a clump from the ground. We cut back this bearded iris foliage to make it easier to get the clump out, but you wouldn’t have to do this for every rhizome that needs dividing.

| 2 of 5

Clean up root ball

Tap off excess soil around the root ball or blast the roots clean with a hose. This gives you a better look at the hard rhizome, so you can see where to cut.

| 3 of 5

Divide rhizomes

Snap or cut the rootball so each piece has a growing tip and fine roots attached. Wait a few hours before replanting these divisions and the cut surface will dry, forming a callous that protects against rotting.

| 4 of 5

Inspect rhizomes

Use pruners to remove the oldest rhizomes (which don't have any foliage) because they won't produce any blooms. Also prune off any rhizomes that are dried out or rotten. Before planting beareded irises, check for iris borers and leaf spot.