If I remember correctly (and Aux can can stomp out this misinformation if my mamory is garbled) Iris germanica is one of the original parent species from which the wonderful rainbow array of tall bearded irises is descended. If that is the case, most of them are quite hardy. I grow lots of bearded iris, 50-75 varieties ( and a few beardless ones as well, Siberian, Spuria) in my USDA zone 3 gumbo garden. "Gumbo" refers to the light gray/tan clay that lies 6-8 inches below the black soil in my yard. I think the gumbo extends down nearly 200 feet, all sediment from glacial Lake Aggasiz. In the heat of the summer cracks develop that I think go all the way to the bottom. You can turn the hose on and run it for an hour without ever filling up the crack. While this may not be the preferred environment for iris, they do grow and bloom, although perhaps a bit smaller. Slugs live in those cracks also. Wouldn't surprise me if species from another hemisphere were able to come up through those cracks. The slugs really do a number on my hosta collection and can make some ugly holes in tomatoes, but I havn't had a whole lot of iris decimation from them.

rich r