When do you plant out?

One thing to consider is space. You probably should start seeds now and ideally have pencil diameter stems by planting time but onions don’t like to be cramped. If you just start a thousand seeds you likely shouldn’t figure on anything smaller than 72 cell trays and that’s a lot of trays committed to onions.

I start a month later in 128 cell trays and roots are still crowded by transplant time. You can give plants 2 or 3 haircuts but you still should not have a packed rootball. One that is held together loosely allowes for much easier transplanting, especially when done into plastic mulch. There are other options but onions, even Candy, are not huge return on investment crop. I think I can do better with later planted bunching onions.

I am in zone 5 and always start my onions in January. I think you should get them started now!

I started mine in January 20. Walla walla and White Spanish. New seed from Andersons seed. Almost no germination. Kinda discusted at this point. I'll give them a few more days, but close to giving up. If I have to plant sets again this year it'll be the last year growing onions.

I started some Sweet Spanish last week. I see they are starting to germinate today.