How To: Make a Terrarium
Nearly any water tight, clear glass or plastic container will do. Look for interesting shaped jars, vases, and even lanterns to create your terrarium. (Scour thrift shops and antique stores.) If you live in a dry area, you’ll want a lid or a door that closes. If you live in a humid area, it’s better to have an opening. A closed terrarium functions by creating its own ecosystem as the plants release moisture, which condenses inside the container and trickles back into the soil. An open terrarium in a humid area works the same way. An open terrarium in a dry area is perfect for cactus and succulent plants.
Place a 1/2 inch layer of gravel on the bottom of the container. Sprinkle a layer of activated horticultural charcoal on top of the gravel. Top with potting soil and then your plants. Be careful not to crowd the plants. Add a little water, but not too much. (1/8 cup of water is plenty for a larger terrarium with 4 – 5 plants.) Add decorative elements such as twigs, pebbles, pieces or bark or anything else you like.