Trim back the stems at the bottom of the plant.
Keep any leaves on the plant if they are still green. Prune the dead leaves, and cut back the tips of any damaged foliage to the base of the plant. Complete this process during the summer months, and then trim the entire plant back within 6 inches of the ground when the leaves begin to change color in the fall.
Coat the bed of the plant with 2 inches of mulch. Because the roots of an iris flower are inert in the winter, the plant does not require any watering during the coldest months.