I really the like the fact that Siberian irises continue to look attractive after their blooms are spent. The stalks and seed pods provide garden interest all summer and into the fall. I wish the bearded irises looked as pretty after their blooms are spent. The downside to Siberians is that it takes so long before they bloom. My Siberian Iris 'Blueberry Fair' finally bloomed this spring, four years after I planted it. It has a longer season than my NoID Siberians.
So, just wondering. What are your favorite Siberian iris.