Thank you for your response, I knew they had to be striated, but didn't know about the possible mutations. I have loads of irises in three colors . I separated and thinned them last year, gave lots away.
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I had 4x8 boxes changed to 2x8, the light gets in better, nothing gets shaded out, I started with peat moss added compost and vermiculite, top with a little manure, I add compost and manure yearly good luck