Since Autumn Fern is evergreen for you, do you think that these are last year's fronds or new ones? In either event, sometimes the best thing is just to trim them off, which often stimulates the plant to put out fresh ones to replace them.

These were this years fronds. By the way, I had this one and another one in a pot last year and as soon as I put them in the ground, they really grew. When you say trim them off, do you mean just shorten them or cut them completely off? Thanks.

Well, maybe something stepped on them (especially those darn deer!). When I say cut them off, I mean cut that frond off at the ground level.

Yes, plants can really grow once you put them in the ground ... I have to keep reminding myself not to keep so much in pots!