Just cut the top 1/3 - 1/2 off with scissors. All my onion, leek, and shallot seedlings need several haircuts before I set them out in late April/May

Should I cut them even though they are only a few inches high?

Onion seedlings start out bent over, looking like green hairpins. They then unfold and straighten up. Looks to me like they are doing what they're supposed to but it also looks like they may need more light.

Rodney

Alright thank you so much. When should I first fertilize the onions and with what for organic growing? Also I put some other onion seedlings outside in my greenhouse. I live in zone 6 and I was wondering if the cold nights would kill the plants? I don't let the temperature go below 40.

Thanks

Mikeman824, alliums are very cold tolerant, I've got all mine outside now, in trays against a southern-facing wall, and its still down to 28-30ºF at night. The two trays to the right are about due for their first hair cut.

I don't know what to advise on organic fertilization for your situation - I have a few hundred starts and when they're in the trays as below, I water them once with miracle grow. They're planted out in pretty rich soil and do just fine.

How long have your onions been growing in this picture?

The two trays on the right were planted Feb 5th, so 38 days ago, the one on the left, ~16 days ago - I didn't write it down, the seed was backordered, came late and I just planted them as soon as they showed up, some too deeply, and there are seeds still germinating in that one.

Will you transplant the ones on the right to individual pots or keep them where they are until you plant them outside? Also, can anyone let me know when I should apply organic fertilizer and what type or organic fertilizer I should use?

Thank you

I'll keep them in the trays until I set them all out. A process of removing a clump of plants and roots, swishing them around in a bucket of water, then teasing them apart.

Here's a link for an organic foliar fertilizer for onions where they talk about fertilizing out after they've been planted. As I said above, I make up a pretty rich planting soil mixing in about 2" of compost, then mulch with grass clippings, and thats all the fertilization I do.

Alright, awesome. Do you make your own compost or purchase it?

I was just curious to see how my onions were doing today and I transplanted some of the cells where I am growing into a 4x4 plastic pot. What I was looking at were the roots. They were not that big. Some were about the size of the top shoot but others were only half or less. Is this a lack of nutrients? Also how many shoots should each plant have? I've looked at pictures online and they all seemed to have multiple roots and shoot per plant. I planted them on March 1st. Do they just need more time? I'm just really anxious to get this right lol.

Thank you

What does your compost consist of?

Oh, the usual - kitchen scraps, spoiled food, mostly yard clean up stuff and grass clippings. I do the heap-it-and-leave-it approach: build one pile a year, then leave it a year. Versus turning a pile it over several times and getting it done in one year. There is a wealth of information on the soil/compost website re making your own compost.

Onions don't require heavy amounts of N right? Do they need P and K?

Onions do require nitrogen. You should think of onions as more like leafy greens than like root crops (which onions aren't). Each leaf equals one ring of the bulb. Meaning the more leaves the bigger the bulb. Aim for them to have about 12-15 leaves prior to them bulbing. And yes, they also need P and K.

Rodney

I planted the onions on March 1st. Should I give them a little fertilizer? They aren't deep green in color. I have a fish liquid fertilizer 5-1-1 and a granular fertilizer 3-4-4. Or should I wait until they are planted in the garden?

Thank you

Well I left for the weekend and my parents never did what I asked them and this is what my onions look like now. Is this from to much heat? Too cold, they didnt put the heater on at night and it got down into the 20s. Lack of nutrients? They are as white as the roots. Any thoughts?

Thank you

Who knows what caused it. Keep in mind that onions, even that small, are pretty tough little guys, and even if the tops fade, a tiny bit at the root end is enough to keep them alive. Keep the potting medium moist, not sopping wet, and they're very likely going to recover.