Siberian Iris Hasn't Bloomed

My Siberian iris plants are two years old and growing in a southeastern facing location. They have never bloomed. I heard irises are finicky.

Siberian iris is one of the easier iris to grow. They tolerate full sun to part shade and moist soils. Avoid high nitrogen fertilizers that encourage leaf growth and discourage blooming. As long as the plants receive a half a day of sun and the soil is kept slightly moist you have done your job. If the plants still don't bloom move them to a more suitable location. Division sometimes invigorates plants and encourages them to bloom.