I'm also interested in growing a little millet, it may be suitable here in
the tropics. Have tried birdseed but haven't gotten any germination. The
commercial birdseed we get is probably radiated or something to prevent
germination.
A type of leaf amaranth grows as a weed here in Trinidad. It is also
cultivated as a spinach crop, but farmers use a lot of nitrogen fertilizer
for this. I have a few plants growing and will try to save the seeds. The
seeds are black and very tiny.