Wonderful idea to make a living hedge but I think you may have a little time to decide how to prune! Is this evergreen? I love your iris colors. I think I need to invest in some real beauties like yours.
Mine are evergreen. In the spring they get this wonderful silvery color and they have lovely fruit that the Cedar Waxwings love! There really is a wonderful variety of iris nowadays - not your grandmothers iris - so to speak!