You can buy iris plants here, put them in the ground and enjoy the bloom, but they won't bloom again. Oh they'll grow, lovely, long green leaves, but there'll be no flowers. It's the same for tulips. It's something about the fact that we don't cool enough in the evenings. Won't do any good to dig the bulbs up and refrigerate them, they still won't bloom again.
I read all about this when we first moved here and it saddened me, I love Irises, even brought some bulbs with me from California. They didn't bloom. So I did some research and found some irises from Louisiana that were ideal for a warm, swampy location. I ordered a half dozen in shades of lavender and purple. A couple of them bloomed, once, and then never again.
That is until now. Two of them are blooming and they're beautiful. That's my minor miracle. I have no idea why they're blooming this year. Nothing is different, we've changed nothing in the garden, but they're blooming. Makes me smile.