I have been freezing Nep pollen for several years with great success.
METHOD
1. Cut the ripe flowers off at the pedicel and put them into a small
paper bag (no more than 10 or you could get fungus). Name and date it.
2. Tape up the bag, put it between some newspaper, and squash it flat
under a heavy book/garden gnome/woman for a few days in a warm spot to
dry.
3. When it's dry put it in the freezer.
And thats all there is to it!!!!
The pollen is viable for about a year. You can also send it to others
overseas and they can re-freeze it and use it when necessary.
My Highland Neps usually flower in Spring and Autumn (12 hours daylight) but
if you pollinate them in Autumn the resulting seed is usually small and
sterile. Obviously day length is an important factor.
As for the one inflorescence per season.... Here's a fly for your
ointment. Ricky Maulder has a N. spathulata with at least 50 (no shit)
inflorescences on it as I write. The main stem is about 10 ft long and
branched several times.
P.S. Fernando - What are you doing chasing dogs around Tokyo? - Too much
Saki I presume....
Bruce