[David]

I didn't really check that area out but there's not direct sunlight. The sun shines on the other side of my apartment. The thing that surprise me was both 3 of the plantlets were growing in the dark in the moss, totally covered by the moss until I dig the moss up. So I guess they can pretty much grow in shade.

Perhaps with the moss covering around them, the temperature is much cooler around the plants as the sphagum moss is kept wet all the time. Humidity is also high.

Also the air outside my apartment is cooler compared to inside my house. Perhaps that's why the sphagnum moss also survives. They never survive in my terrarium indoors.