I've done it -- I just plant the
seeds under/beside the mother when they come ripe. They germinate in late October or the following
spring and as Tammy says, look like little blades of grass, except the kind you have has wider blades, so you can definitely tell the
seedlings aren't grass.
If they come up in October, they stay green all winter and go dormant about a month after the mother. You want to keep them green for as long as possible -- that's how you shave a year off the time to bloom. So you might need to water them if you have drought Mar-June. The little ones -- by that I mean the little Alliums like A. pulchellum, A. drummondii, A. cernum bloom the 2nd or 3rd year, but the big ones like A. christophii are 3-4 years. But you don't notice the wait, really, because they are so self sufficient, for
seedlings, I mean. (You don't have to baby sit them like regular perennial
seedlings.)