Q.Transplanting ferns in the fall
I asked about transplanting ferns in the fall and did not get any information, helpful or useless, about doing this task in the the Fall.
I have to move a large number of ferns that have “naturalized” where I don’t want them, and plan to move them to my wooded backyard in the next week and wish to minimize the number of casualties.

Certified GKH Gardening Expert
They will do best if you transplant them in early spring, right before the new growth comes out. Late dormancy is the correct time to do this. You can, however do this at any time. Just have caution, as you will likely lose a few if they are actively growing when you transplant.
Here is the article for you. This will explain what you need to know: https://www.gardeningknowhow.com/ornamental/foliage/ferns/transplanting-ferns.htm

The information on this website should answer your questions:
https://www.gardeningknowhow.com/ornamental/foliage/ferns/transplanting-ferns.htm
Three elements are key: only transplant on cool days, preferably cloudy ones; move as much of the rootball as possible; and water every few days for 1-2 weeks and then weekly until the ground freezes. Even after the fronds go dormant, the roots keep working to get established. Plant dehydration going into winter is a cause for winter kill.