Leda2,
I think a forum for Hoyas was suggested a couple of years ago but there may not have been enough interest among members to support a Hoya specific forum. Since most folks grow them as indoor plants (along with other houseplants) I suppose the best place for questions, discussing and sharing information would be the house plant forum. If you have questions you can start a thread on the Houseplant forum with the Subject "Hoya" and people will chime in with advice.
I don't get time to visit our "sister" site cubits.org (which is also a free site) anymore but it has a Hoya Forum (Hooked on Hoyas) but I'm not sure how active the forum is:
http://cubits.org/Hoya/
