Generalising (a bit too much) Allium
spp need a fairly rich but well-drained (gritty) soil and they will survive well and possibly divide. If they divide a lot then they will need splitting and the 'bulbs' separating, re-feeding in the process otherwise they will stop flowering.
Growing most alliums from seed is fairly easy (that's why I've got so many): just sprinkle them on some seed compost and cover with light grit, they don't need to be kept warm so leave them somewhere shltered outdoors. The seeds will germinate in late spring but
they will usually need to be kept growing in pots for a couple of years before they are strong enough to plant out.
At this point I should admit that I've never grown A. christophii
from seed but see no reason why it shouldn't work.