Onion seedlings are doing well. Usually go outside to the garden sometime in late March.
With this forecast, would you at least start trying to harden them off? I might have to bring them back in for a day or two here and there, but what do you think?
I probably won’t plant them anytime before the end of that next cold snap around the 18th, but I want to start acclimating them to the outdoors.
Not all onions are equal. I have had two in the toolbox of my truck…all winter. I added one of them to a pot roast this week. (We had single digits more than once…3 for a low I think I recall for the winter).
Same with onion plants/sets, some can handle the 'teens just fine.
There’s not a yes/no answer that is correct to the question posed.
I put things outside whenever it is nice weather, carrying them in at night in plastic tubs, which I can stack near the door. It is somewhat a pain, but I find they grow better outside than in the house. Onions I leave out and cover the tubs, unless below freezing is predicted. The tomatoes and peppers I bring in if below about 45 predicted. I wait until June to plant out the tomatoes and peppers if I don’t want to have to cover the plants with buckets in cold snaps.
I started moving mine out a few days ago. They will be spending the full day outside today, under a vented hoop house, out of direct sun. It is around 60 here today.
I read that consistent exposure of onion seedlings to temperatures below 50 F. for more than 10 days can cause them to bolt, rather than produce big bulbs. I also read that freezing temps will kill young plants. Onion plants less than a pencil in width should be protected from freezing. Most varieties are hardy to 20 F. Plant seedlings outside 4-6 weeks before last expected frost. So you can pick and choose which of this information you want to believe. I do know that little self-seeded onion seedlings that come up in the fall don’t overwinter, but small onions left in the ground often sprout in the spring. Rodents love onions, so protect them with some woven wire, etc.
Mine are a lot floppier and they’re a bit tangled up. I expect the new growth will be straighter once they’re in the ground and can stretch out in the sun. They are getting tossed around by today’s wind.