Somewhere between husbandry, controlled science experiment, and fairy garden lie terrariums and vivariums. You probably already know what terrariums are—maybe a rainforest unit in elementary school prompted you to pile plants into a jar—but let’s get down to the roots: “Terra” means earth in Latin, and the “-arium” suffix is abstracted from aquarium. Add living critters and you’ve got a vivarium (“viva” = life). If you don’t have time to till beds, or don’t have a plot to begin with, bottling some leafy specimens (and introducing live creatures!) allows splendor to unfold on a micro level.
In a terrarium, the trapped condensation maintains a constant humidity. For vivariums involving critters, airflow is necessary, though plants do a great job of purifying it (thanks, carbon cycle!). If you treat your enclosure right, you’ll have a self-sustaining ecosystem that can flourish for months—even years. Here are some helpful tips compiled with video tutorials to get you started:
Step 1: Set the Scale
You’ll want a glass-fronted case or something to keep moisture, soil, plants and critters in. While some fogging is inevitable, a transparent vessel will let you see what’s going on, and when you might need to intervene. A big tank leaves more room for plants to grow, but this Youtube video shows how you can start small:
Then again, if you have an old aquarium tank lying around, or $60 to spend at IKEA, it’s almost just as much effort to secure materials for a bigger build than a smaller one. If you’re going to introduce some wildlife, also consider how much space they need to roam around.
Step 2: Pick an Ecosystem
We tend to think of terrariums as mini misty rainforests, but there are plenty of other biomes to reconstruct. Check out this desert terrarium:
Sourcing plants and critters from your own environs is a good introduction to terrarium-building. With a native set-up, you’ll get up close and personal with the life outside your door (Be sure to have permission to take those specimens!). Plus, replacing plants is just a cheap trip to the yard.
If you’re including fauna in your build, always research their natural habitat to make their new abode feel like home. This guy’s pretty passionate about his ant vivarium:
Step 3: Gather Materials
Many tutorials advise defining the hardscape first by adding rocks or twigs to the terra/vivarium. Depending on how dedicated you are to the arrangement, stock up on spray foam insulation, silicone gel, or other epoxys. Many resources recommend using products that are free from harmful chemicals that can kill beneficial microbes (or worse: the critters you’re keeping.) This aquarium-safe sealant is always a good option. For inspiration, check out how this Youtuber uses a glue gun and spray foam to construct this nifty tank:
After you’ve done some research, start assembling the digs (or literally go out and dig). Make sure to plan from the ground up: The right substrate is crucial to the survival of your habitat. Gravel or clay pebbles allow for ample drainage to keep mold at bay, let roots latch onto something, and critters to burrow without drowning in a swampy set-up—unless you’re after a paludarium (“palu” = swamp or wetland.)
As you’ll see at around 1:40 in the video, charcoal is often added to help purify the water, and a piece of mesh, porous cloth, or other fiber on top can trap finer particles before they clog up the drainage system. Top it off with the right combo of peat, sand, clay, and other natural fillers accordingly. Here’s a helpful guide for finding which soil is Goldie Locks for your plants.
Step 4: Put It All Together
Wait! Don’t just dump everything in there. Layer it like the soil horizons that exist in real nature. If your container has a narrow bottleneck, then a funnel, paintbrush and tweezers will help you with arranging. Make sure to moisten your substrate before you add it to the enclosure. This will set the ideal conditions for long-term success.
What to do about lighting, then? Avoid direct sunlight that could steam your vegetation (and the critters! We can’t forget about them!). Not enough sunlight, though, can result in an under-photosynthesized chamber of sadness. This video has many helpful tips for adjusting UV and water conditions:
Step 5: Watch Life Unfold
If you’re concerned (like we are) about endangering precious critter lives over plants’, it’s a good idea wait until the ecosphere is established, then add some friends to the party, like fairy shrimp eggs (basically sea monkeys…you can watch them hatch!) or newts:
But it’s also fascinating to see how long a terrarium can sustain itself. If you thought things were cooped up this past year, look at this 10-year closed jar time-lapse. It gets pretty primordial, and something is always stalking behind the algae:
Whether your set-up lasts that long, jar life still teaches us a lesson: When conditions are right, and humans don’t mess things up, nature takes care of itself.