DDF, I'll have to take issue with you on that one. Perhaps some of the dedicated nurseries sell the appropriate day length onion for your area, but around here, I can go into a lowes or a walmart and they will have 4 types of onions: 3 short-day and 1 long day
. Something tells me the the buyers for the big-box stores live in the south
Gary, here are some threads on growing onions from seed you may like to read:
[url=https://www.helpfulgardener.com/forum/viewtopic.php?t=22213&highlight=growing+onions]Starting Onions From Seed, Any Experience Here?[/url]
I started my onion seeds indoors about 8-10 weeks before I planted them out. I grew them in front of window light with a aluminum shield behind them to help reflect some light. I gave them only water. I cut the tops back to 4 in. whenever they got long. I did loose about 1/4-1/3 of my crop, due to seedling dying. When I planted them out, they were extremely small; they had maybe about 3-4 leaves each. They looked like blades of grass
However, about 3/4 of them formed medium sized bulbs, with a few of them good size (and that was in marginal soil). The store-bought starts (which were much larger) I planted did perform consistently better, though. I suspect that if I grow the seedling under lights and give them some weak fish emulsion to get them bigger when I plant them out, I will get much better results.
Good luck with yours.