After the blooms fade and seed pods have formed when can I cut back the foliage on Japanese Iris?
Certified GKH Gardening Expert
It is not necessary to cut back the foliage unless it is completely dead. If you would like to "rejuvenate" the crop after being over grown, then you can do this during the cold seasons, when they are not actively growing.
This article will give you more information on the care of these: https://www.gardeningknowhow.com/ornamental/bulbs/iris/growing-japanese-iris-plants.htm