Neighbors, I would love to have some cuttings of a purple dahlia imperialis. I'm new here, and I don't know things work, but I'd be happy to pay in cash. As for trading, I think all I can offer at the moment are some hedychium tubers.
Very few dahlia enthusiasts grow Imperialis. It is very tall and can reach 20 feet. It is very late blooming and in most of the USA it will not bloom or will do so just minutes before a killing frost. It is a different species of dahlia and will not cross with our dahlia variablis. The tubers of Imperialis can be 3 feet long and unlike variablis, it can be grown easily from an inter node on the stem instead of a tuber.