However terrariums can also be 'open', which creates much drier conditions.
A terrarium is a house plant display grown in a container, which is usually sealable and made of glass, such as a large bottle with a cork stopper. The plants are arranged as a miniature garden, with conditions inside the container providing a very different growing environment to outside. Most terrariums are sealed or 'closed', creating a warm, humid environment. However terrariums can also be 'open', which creates much drier conditions. Terrarium plants are therefore plants most suitable for growing in a terrarium, but which plants you choose will depend on whether that terrarium is open or closed.