In answer to questions regarding onions in zone nine. I'm still learning so much about how to grow onions myself. One aspect I'd like to understand a little better is short day vs. long day onions. I believe short day onions are better suited to our zone, although I'm really not sure. Last year I grew several really beautiful onions. They were used up so quickly that I planted quite a bit more this year.
Onions are biennials. They need two years to produce seed. Plant onions in the fall and harvest when the bulbs have formed and the greenery is slightly brown. Pull and allow to dry for a couple of weeks. In our hot climate it is not advisable to leave them outside to dry. The onions might get "sunburned" and then spoil during storage. The best bulbs can be replanted the next year to get seed. Most of this info I got from Suzanne Ashworth's book "Seed to Seed". A wonderful book every gardener should own.