My heart fern (Hemionitis arifolia) has produced a large leaf with spores. How do I know when the spores are ready for harvesting, how to harvest, and how can I grow them from spore? There doesn't seem to be very many guides I could find on the internet on how to do this specifically with heart fern. I've never grown ferns from spores so I'm not sure how much of other 'grow from spore' guides can be applied to heart ferns. I've attached a couple photos including of a close up of the spores under the leaf. Any guidance would be so appreciated!