I have a mixed planter of ferns, and what I think is a Korean rock fern (Polystichum tsus-simense). The planter I've had since early May, the Polystichium(?) for a few weeks. I keep humidity in my apartment around 60-73%. The light is from a northwestern window, and the planter is 1 foot from the window, the other fern is on the sill.

Problem 1:

Over the summer, I let the planter dry off a bit, which caused the expected die-off of fronds. However, recently some of the new fiddle-heads coming in have spontaneously failed, turning brown and dry, especially at the tips. I have been keeping the roots rather wet, am I over-watering? Still under-watering? It it the lack of sun? Too much competition? Any opinions would be helpful.

Problem 2:

My Polystichium(?) fern came in with soaked roots. I left it alone for a week or so but recently watered. It came in with some small browned areas on a few fronds, but recently some young fronds have died, turning dry and greyish with no fuzziness. Does this guy need lots of water always, to dry out between watering, or anywhere in between? When I googled the species, I got conflicting information because I think the common name is shared between a few species. Also, any other cultural advice would be great.

Also, if you can ID my maybe-holly-fern and the staghorn-like guy in my mixed planter, that would really make my day. Though I'm more worried about how to keep them alive at this point ><.

Sorry for all the questions. I'm new to ferns, and I really want to succeed with them.