Oh, I know about foxfire, the luminous greenish yellow glow given off by some decaying wood, for instance.  We had a cabin neighbor years ago who found some on his land one night and ran the rest of us off.  He thought he had uncovered a uranium deposit.     Yikes, it he had and it was glowing we were already too late! 

I suggest tripod, quite dark ambient and long exposure.   You could experiment with some glow in the dark toy then go for the foxfire or just shoot the foxfire as long as you can.  Too much exposure (to air possibly) it seems and this stuff looses its fire..   Sorry, not very specific  but I would have to experiment with it myself.  It will be like photos of dim lightning bugs sitting still.   Best results wished!

Please post any results and perhaps then some can offer better advice.        TomDart.      Hummm..I see you are from Tennessee, also.