Yeah, I know, another kambuckta gardening question, but google has failed me yet again. :rolleyes:
I’m going to try to propagate some bird’s-nest ferns from spores. Apart from some websites saying that home gardeners shouldn’t bother, there was little info available about technique: except that one should collect the mature spore, sprinkle it onto a ‘sterile’ medium and keep moist.
Firstly, how do I determine whether the spore is mature? I did rub my finger on the underside of some fronds, and indeed some came off onto my finger…does that indicate maturity?
Secondly, assuming you’ve done everything right, how long does it take from that first step until a fernlet, (sporelet, seedling, what the hell do you call them??) appears? IOW, when does a spore turn into a little green thing?
try gardenweb.com – sign up and find the appropriate forum to ask about it. Lots of experts there.
Most fern spores are “mature” when they fall freely from the sori.
As for the difficulty you may face, google “alternation of generations in ferns” and note that ferns have separate sporophyte and gametophyte generations.
I was about to make this comment, based on some minimal recollections from 8th grade science class.
I gather that the green ferns we see are the sporophyte generation, amirite? I recall (I think) that the gametophyte generation is very diminutive, so that you might not even ever notice it exists. But I never saw any pictures of what it actually looks like. I got the impression that it might look like an inconspicuous little lichen or similar.
So is that what grows when you plant your fern spores? If so, how and when do those, in turn, propagate themselves to produce the next frondly generation?
Okay, just googled it. Lots of illustrated web pages there.
Sorry to have been so cryptic 
, I was rushed. I taught classes in this, but pre-internet. I was sure you would find more and better than I could type out. Looks like you’ve got it right.
The gametophyte is indeed inconspicuous and the fertilization often occurs via water droplets in the saturated humidity of the culture vessel. A sporophyte (or several) growing up out of the green Saran-wrap-looking gametophytes signals success.