I have been lurking on this thread from time to time because the topic is great and I'm secretly hoping to learn something besides just throw stuff together on a whim and move it around later. The eye-candy has been fantastic! Kudos Neil
I've been quiet because I'm really not an iris person, (although I have way too many of them because my BF loves them and has this thing for rescuing them from wherever and bringing them home
) but I am a big fan of Moonbeam!
I just wanted to say that it has always been reliably perennial for me--I had several when I lived in MN. To be fair, I had deep, black gold for top soil there and everything did well. When I moved here (mountains of UT), I put a few in right away because it does bloom forever and who can argue with that? I killed the one that I tried to grow in heavy soggy clay in too much shade. The other two are doing well, good sized 6yr old clumps--the one in full sun on a well drained slope is the most impressive, although the one in some dry clay, mostly shade, until it bakes in the afternoon sun, is a close second.
I've two more in some beautifully amended soil--they are doing fine, but they are smaller, more recent acquisitions.