Question
Several years ago I bought three Arachniodes standishii. Only one survived the first winter (zone 6, northern NJ), and that one has not increased in size nor number. I've never seen any spores on the fronds.

What is the trick to getting Upside-down fern to grow and multiply?

Answer
Janet hi;

I have not had personal experience with this particular fern, so I can only answer your question from literature.

The company that propagates and distributes this plant in the United States (Casa Flora) provides the following information on its website:  "It can be reluctant to produce spores and then reluctant to drop them, so fortunately tissue culture has brought us this fine plant."

This tells me that, due to the selection and propagation process, it may be very difficult (if not impossible) to try and propagate this from spore.

All my literary references concur that this plant is hardy to zone 6.  That means that you are right on the edge of its cold tolerance.  Once rooted and established, it should survive your winters.  However, extreme cold patterns may prove otherwise.

Generally, the inducement of stress (from heat, cold, or drought) my prompt your plant to produce fertile fronds and spores.  However, in a natural setting, these conditions would be difficult to create.  This variety does have a clumping form though, so while it is a slow grower, one can expect it to eventually grow and multiply to the extent that you could safely take divisions.

I apologize for not being able to provide a definitive process.  This is a fairly rare and unique fern, and it appears that any 'tricks' have yet to be documented.

Thanks for your inquiry!

DC