If it is not receiving enough light, the leaves will stay folded even during the day.
The red-veined prayer plant ( Maranta leuconeura) is a stunning plant that can grow up to 8 inches tall, so consider it for a large terrarium container. The prayer plant received its common name because it folds up its leaves at night, as if in prayer. If it is not receiving enough light, the leaves will stay folded even during the day. Prayer plants thrive in greenhouse-like, humid conditions, so grow your prayer plant in a closed terrarium kept away from cold windows and chilly drafts.