If you mean Stachytarpheta jamaicensis, it's semi shrubby so you could probably keep it in a container over winter if you have a suitable well lit spot indoors. Being a warm climate plant winter sowing won't work. You'd need to start it with heat in spring.

Butterfly wise, since it's not native to your region, it will not support your native butterfly population other than providing nectar for adults. It won't have any value as a larval food plant for the next generation.

I had never heard of Porterweed and had to look it up. Apparently, it's a tropical perennial that grows in Florida and doesn't tolerate frost, but can be grown as an annual elsewhere. There are seeds available on Etsy, Ebay, and Amazon. If you search for "Porterweed seeds", you will find a lot of info about growing and where to get seeds.

I'd be to cautious about buying seed from those sites. A lot people get their fingers burned. There's probably a native plant society seed source.

No, not enough time remaining this year, not even in central FL,

I can send you tons of the seeds that now are on my plants.

So many kinds of butterflies go for these flowers. I have seen hummingbirds drink from the tiny things.

I was on a mission to grow porterweed too. Never got around to it, but the native verbenas are good substitutes. Stiff Vervain, (Verbena stricta) Blue Vervain,(Verbena hastata,) Rose Vervain,(Glandularia canadensis), Narrow vervain,(Verbena simplex). Other hummingbird and butterfly magnets are Cardinal Flower, Cypress Vine, Standing Cypress and Mistflower.

Butterfly on Mistflower, Conoclinium coelistinum.

The Water Snowball Plant, Gymnocoronis spilanthoides is a powerful butterfly magnet. It's native to south America. It grows in water and is hardy to zone 7. It does have the potential to become invasive in Florida, but it hasn't become invasive or naturalized yet.

Thank you all for your replies.

Jay I have Glandularia canadensis and Verbena bonariensis both of which have a VERY long bloom time and I love them. G. canadensis is off and on from spring until frost. V. bonariensis is mostly a reseeding annual here but a small percentage of my plants come back after winter and start blooming a few weeks before the volunteers. I will check out the other verbenas you mentioned. I get lots of cypress vine volunteers every year but I haven't tried standing cypress. My cardinal flower kicked the bucket in our drought this summer. Gymnocoronis spilanthoides sounds like catnip for monarchs. I might watch for that one if it would grow well in a soggy container. I don't have a pond feature. I have Mistflower, Conoclinium coelistinum but have been watching for Greg's Mistflower, C greggii because I think it's supposed to have a longer bloom time than the other. Not sure it will make it through the winter here though.

Floral - I've already been burned by Etsy seeds. lol You are right about that. I've gotten some that were mislabeled and several that had zero germination that were probably very old. I do already have loads of host plants.

Four - Thank you! I will send you a message. Something else that seems to be easier to find in Florida is old fashioned tall pentas. All we get around here are short varieties that don't have nectar.

More seeds, Christie (Pentas, tall).

It is my favorite butterfly plant because ALL kinds of butterflies go for it. And because of its multitudinous spreading by seeds (some gardeners would dislike that behavior).. And because it flowers repeatedly. And because here it can flower also in winter during inter-cold-spell intervals that are long enough.

Four - I sent you a message but something popped up that said "send message error" so I don't think it went through. Do I need to try again?

Best would be to enable messaging in your profile, so that I can test to see what happens when I try to send to you. (It lacks ability of testing by sending to oneself.).

Yay! I conquered technology. I had to go into advanced settings and clicked a box that had something to do with messaging followers. Not sure if that's what fixed it but maybe.

I'm lucky to have a walkout basement with windows on the south and have had pretty good luck keeping plants in there over winter, just treating them like houseplants and I'm hoping that porterweed and pentas will both be happy down there. It's fun to try.