Hi Artlover. If it's mulch you're wondering about, any organic mulch material would be fine............wood chips, shredded bark, cocoa hulls if you like using them....etc. Ferns easily come up through such materials.

If it is a groundcover plant you wish to work with, the choices are many. Once again, ferns are well able to accomodate growing in and among such plants.

+oM

Tom's right.
I use Fir bark to mulch my fern beds, as well as cast needles from my Redwoods.
I also have some contained Equisetum (Horsetails), and mossy rocks as centerpieces
during the Winter. At the moment, my fern beds are full of Forget-me-nots.

Josh