Question
Put ferns inside all winter. Put them outside last week in nice weather but got hit by light frost. About 2/3 of the fronds are dark green now.  The roots did not get it and the base of the fern is still nicely green.  Have not cut anything back and only watered them. Will the dark green fronds come back?  About 1/3 of the fronds are ok and some of them are only partially dark green not brown or black.rw5

Answer
Nick hi;

To properly answer your question, I would need to know what ferns these are.

However, in general, here are my suggestions:

The dark green fronds will NOT recover.  They will eventually become necrotic (brown) and fall off.  To prevent disease from settling in through the dead fronds, I suggest removing them at the base.

Based on your description and depending on the extent of the damage (and the specific fern), I expect your plant to enjoy full recovery.

Thanks for your question and best of success!

DC