i don't really give much care to Egyptian onions. Mine just drop their seed pods and multiply ... I don't even notice ... They grow year around here.
They are great to roast for 10 minutes. The all length of the plant. yummy !
Like drthor said. The small bulbs form at the tops of the stalks in summer. They will drop off and and take root wherever they land on the ground. Of course you can harvest those bulbs and plant the wherever you like. You can also use them as pearl onions.