Those are something that I don't need seeds for - they re-seed themselves more than just about anything around here, and have become a weed, but not something I mind! I can't figure out why they do that, yet the regular, purple flowered chives, while they flower just as much in the spring, don't spread like the garlic chives. I have at least a dozen clumps of those, mostly behind my shed, out of the way, and I never have to plant them!
If the bees didn't like the flowers so much I would use my weedwacker and give the chives a "haircut", before the flowers open up much. Now, I just leave them for the bees, and they keep spreading! My neighbors probably wonder what that stuff is in their lawn that smells like garlic when they mow!