I order from www.mailordernatives.com but I don't think I've ever seen them carry porterweed. Maybe because there is so much confusion. I was doing some reading about it last week and I think even I have the hybrid kind. Apparently, our native one mixes with the non-native one and create something in the middle. Mine has attributes of both. I know I once definitely had the invasive kind because the flowers were much darker (purple, not blue) and they got well over 6 feet tall. I've never seen one in the wild so I feel like I'm not even sure what the native ones look like. I'll have to see if the Florida Native Plant Society is selling them at the next USF plant sale. But one of the things I read was on their website where they were trying to teach all the chapters which one was the native kind because some of the chapters had been selling the non-native kind! It's enough to make you crazy! Well, crazier.
And yes, definitely plant in the fall. It's too hot for people in the summer, let alone people dragging hoses around! That's a big reason I don't do container gardening. Who wants to water every day? And I hate to say it, but I'm kind of glad Impatiens are getting that disease that's killing them. They require way too much water to look decent - even when you plant them in the shade!
