A reader named Wendy asked in a comment where she could find the "Jenny Brook" wallflower in her area. Unfortunately, she isn't registered as a "follower" of the blog, so I have no idea what part of Georgia she lives in, or how to contact her.
The sad news is that, because I buy in quantity, I usually buy direct from the wholesale growers, which was the case with this one. Allan Armitage talked about it at an event, and in my usual way I became somewhat obsessed. I attended a lecture with the curator of the Dallas Arboretum, who also recommended it, and that was the icing on the cake for me! I had to commit to the entire flat of 225 "plugs" coming from Colombia (the country, not the city).
The Jenny Brook comes from Blooms of Bressingham, which is based in England, though they have divisions in the US. According to their website (http://www.bobna.com/ ), they have no retailers in Georgia, but I would guess that if you asked at your local nursery, they could give you more information.