When I lived in California I saw, even had Bougainvillea, it was pretty much everywhere it seemed, living here in
Omaha, N.E I have never ever seen it here. On my drive home from work today I drove past the local nursery as
I do everyday and read their neon banner that stated that Bougainvillea and Hibiscus are all now 70% off.
I was surprised as I did not know it could grow here. I was surprised when I went to California in April and saw
a yard with abundant Holly Hocks, all the 18 years I lived there I had never seen or knew it would grow there like
it does here in Nebraska.

Oh, I just found this: Although it is frost-sensitive and hardy in zones 9b and 10, bougainvillea can be used as a houseplant or hanging basket in cooler climates.

My bougainvillea is in hanging baskets because I can protect them fr-om any freeze in the winter. But they are really hardy in the gr-ound in our Zone9a if old fashioned non-LED -Christmas Lights are used to keep them warm.. In pots, they need water daily in the summer and not as drought resistant but just as beautiful.

Here are mine hanging on our gate along with some portulaca. They don't get full sun all day. And as you can see they are blooming fine. I'd say, as long as you give them some s-un, maybe you can grow them in pots, too?