I love Texas Bluebells! We had some show up wild in our yard in Montgomery, Texas one year. They stuck around for a few years, and then disappeared. I found some sold as annuals in Home Depot last year. Overwintered them outdoors in pots, with a sheet thrown over them when it froze (because they're hardy here, but...y'know, pots).
I've read before that they became so popular in Japan that Japanese wildflower seekers drove them to endangerment here in their native Texas. Most of the versions you see commercially are either grown in Japan or grown in the USA from Japanese seed.
Supposedly they will spread more over winter if you trim back to 3-5" above ground at first frost. Last year when I did that, I stuck all of cuttings (about 8) in a pot. I think I hadn't bought rooting hormone yet, but can't remember. 1 of the 8 made it. The plants DID spread nicely over the winter. I tried dividing the largest one into 3 this spring when I put them in the ground, and that did NOT go well. 2 of the 3 died immediately, and the last 1/3 is clinging to life.
