I had almost the exact same thing happen. I had a bird's nest fern for a long, long time. It was out-growing the pot, It did well in winters underneath the oak so I thought, "Why not just plant it under the oak?" I did so and mine started to follow the same path as some of those discussed above. After watching it get worse and worse, I finally lifted it and replanted it into a new, larger pot. Almost immediately it started to get better. So ever since, it lives in a glazed pot under the oak. It sure didn't like being in the ground - or at least, my ground. Carol in Jacksonville

G'day, my Bird's nest fern has done this as well. Doing some research i read some place that it could be using hard water for a long time. the town i live in is quite renowned for having very hard water so perhaps it is true. I am doing to try watering only with the filtered water. fingers crossed :-)

These ferns are easy to take care of, but probably not a good choice for dim rooms where they will dry out between waterings. Grow them in a bright room but not too near that sunny window. It's essential, with these plants, that you provide an exceptionally coarse textured medium so that you can keep it constantly moist without fear of causing root rot. The typical houseplant potting soil won't work. As far as humidity goes, I never accomodated mine in any special way. No trays, no misting in my house. But I do not overheat my home in the winter nor do I chill us out in the summer. Both of those bad practices dry the air like crazy! I'd avoid using BNF if you need something sturdy, a thrives on neglect kind of plant. My guess is that you can't keep the potting medium moist enough in your maintenance schedule. Yes...do use distilled water for houseplants to avoid chlorine, fluoride.

They're tough as old boots but don't like waterlogged roots. Plant it in a piece of hollow tree stump, an old tyre slashed at the bottom to let any water drain out, or just in a large very large plastic pot, anywhere it can have excellent drainage. Don't need any soil, throw a bit of leaf litter in the bottom and the fern will be happy. Although an epiphyte that will grow on trees etc, they need less water when grown within a contained area. I live in Qld Aust where they are native, and have them coming up everywhere on my trees. I then transplant small ones into ordinary black plastic pots of very well drained composty material and they flourish.