The Douglas iris plants we propagated a few years ago are doing well. We just did some light pruning, the only maintenance they require.
A California native plant, the iris douglasiana does well in partial shade. The irises shown above get only a couple hours of sun a day, shaded by the house and a large California live oak (quercus agrifolia). Low and green, irises look nice along walkways.
The irises below get mostly sun. The before-pruning photo on the left shows the spent blossoms and old leaves that can be cleaned up. Pull aside the mulch to expose the leaves. Then prune the spent flowers/seed pods, and replace the mulch. We use oak leaves as mulch.