Bearded iris are wonderful in the spring, with their tall stalks and large, showy flowers.  If you want to continue the show, you have to take care of your iris, and that care includes lifting and dividing them about every three years.  If your iris clumps are congested and seem to be producing fewer blossoms than in years past, chances are it's time to take this step.  Fortunately, it isn't hard because iris rhizomes thrive close to the soil surface and have shallow roots.

To divide an iris clump, trim the long iris leaves so that they are only about two inches tall; then take a spade and dig all the way around the clump, gradually lifting it away from the surrounding soil.  Knock the as much soil as possible off the mass of rhizomes so that you can see what you are doing.  Divide the clump into pieces, making sure that each division has the remnants of a leaf emerging from the rhizome.  Discard any rhizome pieces that are soft, spongy or shriveled.  Amend the soil with compost or other organic fertilizer.  Replant the healthy divisions close to the soil surface, spacing them six or more inches from each other so that they will have room to grow. 

You will probably have some spare divisions.  Plant them in other locations on your property or give them to friends.  Trading rhizomes with other iris lovers is a great way to acquire different colored iris and expand your collection.