blue iris turned red and white and yellow

Question

Why would 2 entire raised beds of irises (all shades of blue) all be a different color this year when they have been beautiful blue for 3 years? They are under crape myrtles. No dogs in this fenced yard. I created the beds so nothing planted there before. The “new” irises are solid red, red and white and red and yellow. The ground is clay and tends to be too wet to plant so we made the raised containers each about 4’X5′. and filled with about 18″ of amended soil. The Crape mytles are almost 20′ tall now and the irises have done very well beneath them and been shades deep blue to light blue for at least 3 yrs. now.

Answer 1

I can only offer one solution, and that is because iris color is, solely, a genetic trait. The only thing that I could think of that would have caused this is outcrossing, or hybridizing with any nearby beds of colored iris. They can drop seed, and germinate, which would cause the iris colors to take the trait of both, or either of the parents.