How to Divide Iris
Iris—especially the reblooming varieties—can be so energetic that crowd control becomes necessary after a few years. This is your guide to dividing an iris.
Time to Divide
When clumps of iris start elbowing each other for room, blooming might be affected. Dividing them allows your flowers to rejuvenate so you can enjoy their beauty both in the yard and around your home. The best time to divide is typically late summer or early fall.
Here's what you'll need:
* Garden fork
* Garden gloves
* Powdered dolomitic lime
Step 1: Dig Up Iris
When iris clumps get too dense, it's time to divide. Using a garden fork, poke deep beneath the clump and dig it up.
Step 2: Pull Apart
Pull the iris crowns apart, separating as many pieces as possible without damaging the roots. With rebloomers, the foliage should not be cut back after spring blooming.
Step 3: Fertilize
Wearing gloves, sprinkle one cup each of dolomitic lime and fertilizer onto the soil. Work it well into the soil.
Step 4: Replant
When replanting, dig a deep hole (8 inches or more) and angle the roots straight down rather than splaying them out. New growth will come from the heel of the crown, so face them accordingly.
Step 5: Water
Firm the soil around the rhizome and roots, then water the transplanted clump generously. If precipitation doesn't oblige in a week, water again, but don't overdo. Irises dislike overwatering.
Iris look beautiful in your yard, but they make excellent cut flowers too. (Some varieties are also especially fragrant.) Pick them early in the morning so they're full of moisture; cut at a 45-degree angle where the stem starts to turn green; and place in a container with cold water as soon as they are cut.