I'm growing seedlings in a greenhouse and they are too tall for their trays. I planted them according to the time line in the instructions.
Growing Seedlings in a Greenhouse
Certified GKH Gardening Expert
Greenhouse instructions are only a guideline, not an absolute. Judging by your photo, I would say it's definitely time to take your dome off since your seedlings are outgrowing their space.
Thank you. Will they be safe? It's still really cold at night. Greenhouse is only old windows. Trays are on heat to maintain root temp.