"If they are willing to Gainesville, FL - The Butterfly Rainforest at UF Museum of Natural History has a supplier they get their Milkweed from that is Pesticide free and always looks good. They sold me 18 plants last fall and we release 150 monarchs in November.http://www.flmnh.ufl.edu/butterflies/
They can call the University of FL and ask they pick up an order for them. This is the main # for the McGuire Center. (352) 392-5894 Be sure to ask for someone that is in charge of plant sales.
Hope this is helpful!