I've ordered from them in the past, and received nice, correctly name rhizomes. Depending on the grower, orders generally open anytime from mid-January to June, with some carrying on into fall. Many of us order the moment a grower opens to ensure we get the iris we want before they sell out. The growers usually offer a window of time when they send. It's usually July and August,with some being in September (or later). The AIS website has a lot of good information on growing and culture.
All growers will have instructions on their websites (if they have one). If you have doubts about how to place an order, most will answer an email to help you out. Some still do business by mail only.
