You can really use anything for a terrarium, as long as it is glass. You can even use heavy plastic, but I prefer the look and feel of glass.For your terrarium, look for a jar or container with a wide mouth. While it is possible to use something with a small opening, it is much easier to add plants if your container has a wide mouth. Also, keep in mind that ideally you don’t want your plants touching the sides of your jar; so the wider the bowl the more plants and soil you’ll be able to fit.
Also, keep in mind, if you use a large container, you will have a greater choice of types and size plants you can use as well as the option of fitting in decorative elements, such as shells, figurines or ornaments.
I found these jars that are perfect for terrariums at a discount store - all cost $7.00 or less. I chose them because I wanted to make an arrangement of three terrariums that would sit on a corner table.