Ammi seedlings - pinch out?

Grajean

I sowed Ammi in September same time as Monty and have kept the seedlings in my cold GH. The seedlings are looking healthy but are now about 5 inches tall, should I pinch these out? Due to heavy frosts I did bring them indoors but would they have survived in the GH without any heat? 

fidgetbones

Ammi don't need heat or pinching out.

Grajean

Thank you, back to the GH tomorrow.