in worked soil plant 1/2 to 1 inch deep I did not mound and they came up nice last year

I hate to burst your bubble but you're way too late for onions now. Another case of the big box corporate bean counters selling veggies here that they sell throughout the country without regard to our Florida climate differences, totally inappropriate now but they count on the fact that less than one in ten will ask for their money back. Wait a minute, I just made the case for their brilliance :-(

tom's right but you can stick them in the garden anyway and just eat them as scallions and new onions. they'll thrive until the rains and humidity really kick in.

next year--sweet onions go in as early as you can find them, ideally in august but as late as nov or dec. they are easy, delish, but they take up a lot of space for a lot of time...

Onion sets? Small plants or small bulbs? If it is small plants, go ahead and plant them about 6 inches apart with the base of the plant about a half inch deep. Rows should be at least 1 foot apart. You might not get mature bulbs but you will at least get green onions from them.

If you are talking small bulbs, go ahead and plant some 2 or 3 inches deep, 2 or 3 inches apart in rows 12 inches apart and again, you will at least get some green onions. Take the rest of the bulbs and put them in the crisper drawer in the frig. They will keep until this coming fall when you can then plant them for growing bulbs.

Keep in mind that Florida needs short day onions. If your "sets" aren't short day, all you can probably hope for are green onions. Which ain't all bad, I love green onions.

I second the Egyptian Walking Onions. This is the second year I've grown them and I use them constantly and don't really give them a lot of care. Granted, they aren't big, juicy, sweet onions, but they meet my needs pretty well.