This year my bearded iris bed outdid itself. No pests. No rot. I didn't add fertilizer either. Each rhizome sprouted a stem with multiple blooms of dazzling beauty. I enjoyed spectacular color for weeks. Delicate petals of yellow, bronzy reds, blues, lavender and peach glistened in spring's sunlight as this monocot lived up to its Greek name for rainbow.

I think I owe the season's spectacular performance to the rain effect.  Yet I can find no research to support my supposition. While bearded irises can tolerate less than perfect soil such as clay, they often don't survive if their roots stay soggy . And with Vacaville's 40 plus inches of rainfall this fall and winter, that's more than a few days in very wet ground.
      
In fact, The American Iris Society uses bold font to emphasize “Over watering of Irises is a common mistake.”  I know this is true because in the past I've lost several rhizomes to over-mulching in winter and over-moisturizing in summer. Unlike the true water iris, bearded iris don't like their crowns covered or drown.  So what's up?  I don't know for sure yet. But I'm hoping for a razzle-dazzle repeat performance next year. And, yes, I regret that I missed April's weekend show at the Pleasants Valley Iris Farm. It must have been awesome.

For additional information on growing bearded iris (a.k.a. pogon iris; pogon meaning bearded in Greek), see the following:     

http://www.extension.umn.edu/garden/yard-garden/flower/iris

http://www.irises.org/About_Irises/Cultural%20Information/Grow_Bearded.html

Also available for viewing is an article on Water Irises by Greg Speichert at
http://www.hortmag.com/plants/plant-profiles/water_irises