onion seedlings: trimming height and transplanting Qs
I'm growing onions from seed and they're under lights right now. I started them 3 or 4 weeks ago and they're about 3 to 4" tall. I've read that you can cut them down to about 3" before planting, but I'm wondering if I can trim them now. They're almost touching the light, which I can't raise any higher.
Would trimming them inhibit their growth or otherwise harm them? If so, I'll have to figure out something else...
Also, at what point can they be transplanted, both in terms of their age and the temperature outside?