Question
I purchased a house that has a lot of iris. They have multiplied and I would like to know how to separate and transplant, and is now (may) a good time in Colorado?
Thanks for the advise.

Answer
Hi Lori,
Thanx for your question.  You can transplant iris most any time while it is not cold and freezing but I would wait until late August.  Cut the foliage into fans about 4 inches above the rhizome.  Did the clumps up and start removing the dead and/or dried up rhizomes.  You may notice some that appear to have been eaten and you may even find some worms or iris borers in those rhizomes.  Discard any infested rhizomes or any that look like they have been infested.  Do not compost as this will not completely kill them.  You'll need to either burn them or have them hauled away with other biological refuse.  Plant the separated rhizomes 12 inches apart.  Every three years, you should revisit this process to keep the iris healthy and blooming optimally.  Most of the time when separating rhizomes, they will come apart rather easily.  You may want to dust broken and exposed rhizomes with an anti-fungal powder available at the nursery but I have not encountered problems if I replant immediately.  I hope this helps.
Tom