I have a number of different ferns in one terrarium. Most are browning and dying. From my research, I have read that the main reasons for the browning are:
1. the soil being too dry
and
2. low humidity

Below are the conditions in my terrarium:
• I leave the top of the terrarium open a bit. There is a mist on the sides of the glass.

• The terrarium in under an eastern facing window and does not receive direct sunlight.

• The ferns are in a mix of potting soil, charcoal, and chopped sphagnum moss.

I think I will gradually adding more and more water.

Any thoughts or suggestions would be greatly appreciated!

Thanks!
Jeff

No hydometer, but that's a great idea, considering I have so many terrariums... Thank you!

I have maidenhair ferns, rabbit's foot ferns, creeping fig, and your typical ferns (don't know the names). I bought them in the flower district here in NYC. The ferns I find all around our upstate weekend home seem to do well under any conditions.

I've been keeping the lid off of the terrarium and there is no condensation, so hopefully, this will do the trick... if not, I suppose I'll have to pay attention to which varieties do well and remove the varieties that are dying.

They're getting plenty of light as they are under an east facing window that gets full sun. 75-76 degrees temperature.

Any other suggestions would be greatly appreciated!!!

Yours truly,
Jeff

I am leaving the top (tapers to 4") open... terrarium is 15" w x 16" h. A misting once a day is making all species happy, healthy and fronds are popping up everywhere!

Thanks for the help everyone!