Hi,
I have real space limitations here, and so when I get orders with bonus included, I have to plant many of these irises in containers (it's that or give them away). Often, mine are in terracotta pots which are not really big enough to accommodate their root systems. They definitely grow, but they don't thrive under those conditions. If the pot is big enough, though, they might bloom very well (I posted a pic of Secret Rites on the gallery site, and it is in a pot). Irises will work in containers, but it's not ideal.

At least, this is my experience.

Mike in SC