I think that's a great idea! I have three "Butterfly" daylilies, although I've only had one of them bloom for me. I just looked them up, and BLUEBIRD BUTTERFLY (my bloomer) is 4"/28" tall, AZURE BUTTERFLY is 4"/31" tall, and VIVID BUTTERFLY (sent to me by Floyd Cove as a gift this spring) is 4.75"/36" tall. So your bloom size is right in there.
