Question
What is the smallest lowland nepenthes species (or hybrid) best suited for terrarium growing?

Answer
Hello Jaden,

A couple that I know of, N. gracilis, and N. bellii, may be small enough to get into a terrarium. I generally do not grow Nepenthes in a terrarium, so my experience with terrarium suitability is limited. I grow all of my plants (typically plants that will grow in the environment I have available) open pot to reduce mold and increase my ability to monitor their water requirements.

Christopher