The time to clean your iris patch in the spring is when the leaves are starting to appear.  That is usually mid March here on the Front Range in Colorado. Removing dead leaves and other debris should be done now to avoid injury to leaves as they get larger. With all the extra moisture this winter, chances of root rot are greater. Cleaning the debris will greatly reduce this occurrence. 

At this point you may already see aphid activity.  Aphids love to hide in the leaf structure close to the rhizome.  Many times they are quite invisible until you see damage later on the leaves and flowers. I use BioAdvanced Rose and Flower care and then I don’t have to worry about damage through the growing season. This is a systemic product that will last the growing season and provide some early nutrition. Heavy water spray will not affect the aphids.

If you didn’t get your iris divided last season, here’s an easy tip.  Cut the old rhizome material off with a sharp knife and just leave it.  Same with any rot.  Try to cut it off and pop it out of the ground.  If your rhizomes are too deep and bloom is affected, wait until the soil is warm, then try to pry the rhizome to the top of the soil with a potato fork.  You may do these two steps in combination.