They love ground-up limestone. My problem was treating them like a "normal" fern instead of the seasonal ferns (wey winter/dry summer) they are.

Yep! They drown in a container with a water reservoir (from my experience).
And they don't like mulch against their crown, either. I've been moving the
redwood needles and oak leaves when they get too deep/close to the fern.

Thanks for checking it out!

Josh