Onions are curious creatures. I've been trying too and have had varying results. Last year, I tried starting onions seeds on March 1 in paper egg cartons. It quickly became obvious that the containers were too shallow, when the seedlings stood up, they grew roots that were as long underground. Never-the-less, I had a few standing toothpicks to transplant by mid-March and I did. Out of the dozen, 3 or 4 survived and produced golf ball to billiard ball size onions.
Last fall, I planted Egyptian onion sets and Yellow Potato Multiplier Onion sets. I only vaguely remembered where I planted them when spring rolled around. I think some I planted around the apple tree have rotted as that area stayed wet during the early spring thaw. Either that or I trampled them when I walked around the tree pruning in early spring.
I'm pretty sure that the onion-y shoots growing in the same row as garlic ARE Potato Onions though.
I also went around tossing onion seeds among the mulch around 2nd week of March when I sowed my first pea seeds.
I planted onion sets too.
I also had some onion seeds started on Feb. 5. using toilet paper tubes as bottomless paper pots. Come planting time, these were a little bit sturdier than last years seedlings -- about 4" tall -- but they suffered from lack of nitrogen mid growth. I think because the cardboard locked it up (I overcame this by watering with oyster mushroom substrate leacheate. When mycelium started to grow on the cardboard, I watered with liquid fish fertilizer and the seedlings turned around.) Anyway, so I have those planted around.
I also planted out some of my onion bottoms that had been growing in containers indoors all winter.
Guess what? I haven't kept notes.
I have onions growing everywhere except near peas. Some doing well, some not. I don't even know which one's which except that I grew some Red Robin onion seeds and planted Red Whethersfield sets. So the red ones that are much, much bigger are the Whethersfields.
I can tell you, though, that you know you're growing direct seeded onions in the garden when you have to adjust your "mental weed filter" so as NOT to pull up grass-like "weeds" when they are tubular.
I have leeks from seeds too. They're still in their flats because they're so small. But I'm going to pop them in the ground this weekend.
I think my next experiment will be to try starting onions from seed IN THE FALL. ... NO WAIT! That's not what I wanted to try. I remember now -- I want to try [url=https://www.helpfulgardener.com/forum/viewtopic.php?p=123679#123679]Gary350's Grandparents' technique[/url]