Hi DeeM!
The Dietes, AKA African Iris, or Fortnight lily grow well for me in California. I've got a couple different species and they get no watering, no pampering. I do cut off the bloom stalks when they're done blooming so I don't get a million seedlings. I hadn't heard of 'Katrina', so I googled and came up with this from Perino's Garden Center:
"At the time of Hurricane Katrina in September 2005, Buddy and Peter Perino had been working on producing a new variety of the African Iris. In the months following the storm, this new iris proved to be particularly hardy, and the Perinos eventually patented it and named the variety ‘Katrina.’ It differs from other iris varieties in that it has a higher tolerance to poorly drained soil, heat and humidity. The Katrina Iris also sets fewer seedpods, resulting in a longer bloom season. Buddy and Peter Perino have donated the trademark royalties for the Katrina Iris to the American Wetland Association, benefiting wetlands restoration projects."
Back in my old neighborhood, the parkways were landscaped with Dietes iridioides (Fortnight Lily). Every February, they would cut them down to the ground. The idea was to get rid of all the old brown foliage and force fresh new growth.. It's the only place I've seen it done, but it was really effective. I don't do that.. There always seems to be too much to do in the garden in February that is of greater importance..
