All plants do better in an environment that suits their needs. Iris are no different. Bearded iris tend to be less demanding in their requirements, but different classes and varieties can need distinct care.
Beardless iris, like Siberian and Japanese iris, can vary widely in their growing needs, with Japanese iris being the most demanding. They all will look their best two to three years after planting.
Iris Care and Culture
Iris ensata, Japanese Iris
Iris in Containers