I love this plant and ordered two of them as well as four of the two yellow versions. I have double dug flower beds with plenty of compost-- sun from morning until 2 PM, then a couple of hours in the evening. My lilies in this bed do well, so I assume the drainage is good.
One plant did not come back after winter. The second did well until about the 4th of July, then, quite suddenly, it started to "wilt" and was dead within a few days. The larger of the four yellow ones was still going strong until last week. I see one of the spectacular big yellow ones has started to wilt as well. I have pruned the dead parts out, but they keep coming.
They are neither under nor over watered. I can't see any kind of bug on these plants, and those plants interplanted with them are doing fine.
Breaks my heart because I built one whole bed around them for my daughter's outdoor wedding at the end of August. They are among the few perennials in bloom at that time. Too late to try and replace them with something big enough for their function in the bed.
I've been gardening for 30+ years and rarely have losses. I have no idea what I did wrong, so am afraid to order again at the hefty price plus shipping.