I have a micro climate next to the house where irises always bloom first. I've found that if I'm interested in using some later blooming irises on earlier blooming ones to make crosses I can put the later bloomer near the house, and the earlier bloomer out farther, and they bloom closer so I can make the crosses. I also have put some in both places so I have access to them for crosses for a longer season. If it's a favorite of yours, you could do the same thing just so you could enjoy it longer.
(Provided you have a micro climate some where.) I'm also experimenting with having a "very late" bed where I put later bloomers in an area with a bit of shade. Any thing to extend the season!
