Define the case type first (closed humid, open humid, open arid), then choose plants that evolved for that niche.
Mixing ferns with echeveria is the classic failure mode: one wants recycled humidity; the other wants dry airflow.
Shop labels saying “terrarium plant” are marketing, not ecology. Prefer pest-free indoor plants and quarantine newcomers.
UK winter central heating dries open bowls but can also push condensation chaos if you overcompensate with misting in closed jars. Never put a sealed humid case in direct summer sun — glass magnifies heat.
