Hi Sam,
I did a search at
www.google.com and put in the search box:
propagation + allamanda +
seed and got 265 hits. I too am having trouble finding the info you want. Most sites say to propagate from cuttings, though one site mentioned that the person put the
seeds in a
growing medium and waited until they sprouted. They just didn't say how long. It was the first one here.
http://www.google.com/search?hl=en&q=propagation+%2B+allamanda+%2B+
seed&spell=1
Sorry I couldn't be of more help, but a repeat of the search, or going to that link might be helpful. I wish I could could grow them in my
zone 7 garden, but at least I did get to see them in their native habitat and it was wonderful.
Good luck,
Newt