I am in south Louisiana. Zone 9 or 10. I had a Mandevilla that grew great.
Towards the fall, it produced some seed pods. I googled and the information
said for the seeds to be mature, to let the pods get brown before harvesting
the seeds. We've done that, in fact the pods opened by themselves. The
little seeds in the pods have "feathers", much like oleander seeds.
I have google and can not find any information on how to germinate the seeds
and possibly grow my own mandevilla.
Right now, I have some planted in some started peat pots. Everything else I
have planted has come up, but nothing from the Mandevillas yet. It's been
maybe 7 days.