I have an outdoor rabbit’s foot fern under redwood trees. What kind of fertilizer should I use for it?

Question

It provides a border along the grass in this spot under the tree and
never has been fertilized. Been there at least 15 years. Yes, I did
say it is costal redwood trees, three of them here in So CA.

Answer 1

Use a slow release, mineralized complete organic fertilizer. Be sure to establish a good, deep watering program for your coast redwoods through the hot dry summer and fall.