That's part of the terrarium's appeal. It's a mysterious little microclimate that makes you think of jungles or deserts. Another appeal is that they are very self-sustaining. The moisture creates its own "rain cycle," so they rarely need to be watered and many do well in low light.

First, I purchased glass containers. The small globe is from Sprout Home, the square bowl is from Jamali Garden Supplies and the darker glass is hand blown by artisans in San Miguel de Allende.

I purchased some of the smallest plants I could find, including Oxalis, Maiden Hair Fern, Evergemiensis Fern, a Red Vein Fittonia, and some moss. (At this point you might be noting that my plants are a little big for my glass containers. I wasn't yet aware of this.)

Here, I've added way too many pebbles. I then added too much charcoal, and by the time I added the soil mixed with a little sphagnum moss, it was too deep. So I had to go back and take out the soil, remove some charcoal, and some pebbles.

Almost all the plants I bought were too big to fit into the globe, so I ended up filling it with moss and a few oxalis.

The ferns, moss, Fittonia, and Oxalis are essentially crammed into these. They aren't the tropical landscapes I was hoping for. Though, I kind of like them; I felt a Victorian Era-type fetish of wanting to cram all of my plants into glass jars...

But next time I make a terrarium, it will be with little plants and big containers.