They are tropical, native to India. I researched and decided they weren't something I could grow. You would have to protect them from freezing weather.

Maybe they are growing them in containers or in greenhouses or some sort of warm microclimate (like a courtyard enclosed with masonry walls on all sides). Aside from the fact that they grow in tropical/sub-tropical regions, they also need perfect drainage and don't tolerate overwatering. This year, if grown in most parts of OK, that whole overwatering (by Mother Nature) thing would have been a problem too.