Carol,
If you want to start onions from seed, mid-October is a good time to seed 1015 onions. These are onions developed by Texas A&M and are very good tasting.
We usually get our onion sets in late Feb. or early March and set them out. Almost any store with a garden area will have onion sets, and also most feed stores. I can't recommend any particular variety, since we get yellow, white, and red onion sets--whatever is available.
Butterflies and bees love the onion blossoms, but letting your onions set blossoms will shorten their shelf life. Reds are not long keepers, as are the sweeter whites. The yellows keep best for us. You may want to post a request for variety suggestions on the Vegetable Forum.

I guess I'd better plant lots since I do want some to flower. I've had no luck with (ornamental) allium and figure these will have to do. I hadn't thought of starting from seed, but I will give that a try. Thanks, marlingardener, for the info.

I love to grow onions! They last so well in storage, unlike most anything else you can grow.

When you start seeing them at feedstores and other places, that's the time to plant them.

Dixondale Farm is a Texas onion company.

Here is a link that might be useful: Dixondale Farms

Be careful not to buy onion sets too early. If you put the onion sets in the ground too early, the temperature fluctuation will cause the onions to think they have grown two seasons! IF that happens, they will send up flowers (Bolt) and you wont have any bulbs to store. I used to buy my onion sets as soon as I saw them on the shelves at the stores (Jan-feb) but I had problems with bolting, so I tried waiting and then buying them in March. Ever since then, I have only one or two onion plants that bolt out of every 100 plants or so. Good luck!

Tim