Irises seem to be somewhat divisive, people either love them or hate them. Many times they are passed down from generation to generation. I am a big fan for several reasons. I like anything in the garden that carries emotion or nostalgia, I also cannot ignore the fact that they are hardy and seem to prefer a level of neglect! Because they can be so prolific, they are easily shared between gardeners. The ideal time to thin or separate them is in the Fall so that they have time to get re-established in time to be fabulous in the spring. But, they can also be transplanted in the Spring especially before it gets too hot. Maybe your garden is missing this elegant perennial?