Most varieties send up a flower stalk with several blooms that open incrementally.
The spent flowers also will direct energy into producing seedheads.
Irises are vulnerable to blight, leaf spot and soft rot.
Bill Koplitz / Getty Images
Larvae hatch in spring and eat through the leaves eventually boring into the plant’s rhizome causing rot.
Regardless of the iris variety you choose for your garden, steps for cutting back remain the same.
Use asterile hand pruneror clipper to cut the stalk at it base.
Angled cuts are best because they allow for water run-off which helps prevent moisture-based disease.
The fan trim is a good garden practice for maintaining and encouraging consistent annual blooming.
Clean, sterile scissors, hand trimmers or a small garden shear all work well for this task.
Starting in the middle of the clump, cut at a downward angle along each leaf.
leaving a graduated fan shape of 4 to 5 inches tall at the peak.
The outside leaves should be 2 to 3 inches tall.
At this same time, go ahead and remove dried, discolored and diseased leaves.
Now dead foliage should be removed leaving just a half-inch to an inch above the rhizome.
This is a good time to run your hands over the plant’s base.
In a good sized iris clump you will find a number of rhizomes fairly close to the soil surface.
Check for spent or soft ones and cut them out with your clean tool.
https://www.missouribotanicalgarden.org/Portals/0/Gardening/Gardening%20Help/Factsheets/Iris22.pdf
