Terrariums are usually sealable glass containers that can be opened for maintenance and to access the plants inside. However, this is not essential; terrariums can also be open to the atmosphere rather than being sealed. Terrariums are often kept as decorative or ornamental items. terrariums create a unique environment for plant growth, as the transparent walls allow for both heat and light to enter the terrarium. 8 plants included in 2.5 pots approximately 4 to 6 inches height of the plant and the we have variety of plant it will depend on the season and instructions included.