[Kajazy]

I have some little celery seedlings, about 3 inches high, out in my cold frame (it's a plastic jobbie - not very sophisticated) - do they need to come indoors during this frosty weekend, or are they ok out there...?

[Trillium]

celery seedlings can easily fall to frost so its worth bringing them in for now. When they're a larger plant, they can take a lot of frost, but when young, no, they can't.

[Salmo]

They are suseptable to frost. In any case if they are too cold they may bolt to seed so bring them in, at least overnight.