A terrarium can be made creatively in a way you want. There is no hard and fast rule or necessities that are absolutely required. Yes, but the basics are the plants and a glass jar and some soil media. A Terrarium can be custom built as per your requirement.
Some of the things you need are as follows:
- A glass or plastic container. Glass is always preferable.
- Rocks, if you choose. But recommended for creating a false bottom.
- Moss, if you choose.
- Soil (growing medium). A garden soil for direct use in terrarium is usually not recommended.
- Plants that won’t overgrow (generally miniature or dwarf plants)
- Spoon for placing soil.
- Long tweezers for putting materials into vessel. Also called as Aquascaping tweezers
- A net to separate false bottom layer from soil
- Spray bottle or syringe to water the terrarium.
- Decorative miniatures
- River sand (for decoration)
- Pebbles (for decoration)
- Charcoal for keeping the terrarium free of toxins.