I feel very honoured. I received 42 of those elusive seeds ... Because of BB20. I have no experience at all with grains. I found this thread because I searched for the needed information.
The information is not really unambiguous ... But because I have the seeds now, in September, and some say it can be sown in September, I think it's best to sow it now. Maybe sow 30 seeds and keep 12 'as a reserve'.
I think I'll sow it at the spot where I did grow flax before, there's still nothing but sedums (my 'living mulch') growing there. In general the soil in my garden is not rich (it's sand plus compost and mulch I added the last 5 years). I understand Sepp Holzer grain is doing well in poor soil.
I read about cutting, scything or mowing it, so I'll cut it (with scissors) a few times next year. And then hopefully in 2022 it will give new grains. To share with others who can grow more, etc.
"Also, just as you want men to do to you, do the same way to them" (Luke 6:31)