Beginner Gardening: Fern: diseased or just old?, 1 by _Nadine

_Nadine wrote:
I think I have some sort of disease attacking my ferns (I think they are sword ferns?). The spots are appearing on older fronds. I don't see any spots on the new fronds yet but it's pretty widespread over the other fronds.

If these are diseased, would someone advise me on how to treat them or point me to a solution? We are in Oregon and have many ferns - which I love, so this is quite distressing. I want to keep them but have no clue!

Thanks,
Nadine