There is an iris for nearly every conceivable environment, from arid desert conditions in full sun, through damp conditions in shade to permanent immersion in water. The wrong conditions will kill the plants, so it’s important to buy the right iris for the chosen position.
Having said that, most iris can tolerate a certain amount of variation in their growth habits, for example bearded iris will usually live through a very wet summer, though may need a little extra care.
The BIS can provide members with instruction booklets on how to grow iris in your garden, which will help start them off well. [Link to publications page]