I'm hoping I can pull off perennializing them here in 9a/8b.
We're in an 8/9 zone here. I got a handful of seeds and planted some 2 years ago out in the
yard, and they died in the winter frost of that year. I have one growing under the eaves in a south facing planter box, and it's surviving the winter, so far. I got a handful of seeds from it over last summer to cycle into next year. Just before the weather started to get really cool, I cut it back and chopped the leaves into the planter box to keep it all under the eaves. It's trying to bloom again, even in the cold! I'm not sure if the flowers will produce, though.
I am surprised at how tall it's growing! I never expected them to get so tall.
I
think I might plant some more to break up the 105* F summer sun for a few plants that can't take the heat and just accept that they won't survive, just plant the seeds they put out the next year again, and grow it as an annual protector plant.