WHAT, EXACTLY, IS A TERRARIUM?
Imagine a jungle, a desert, or a forest habitat thriving in your home in a space as small as a light bulb. Terrariums replicate outdoor ecosystems indoors for your observational pleasure; they’re gorgeous; and they can thrive in spots as unlikely as the top of your bedroom dresser. They also make fantastic gifts. (Hint, hint.) Literally a “place of earth,” terrariums are part of a larger family of vivariums, or enclosed areas for raising plants, animals, reptiles, insects, birds, or fish.
So, what is a terrarium? Housed in a glass structure—such as a jar or, yep, even a light bulb—for easy viewing, a terrarium typically contains habitat-specific plants, as well as a mixture of pebbles, leaf litter, and/or soil. What goes into your terrarium should be determined by factors including moisture, lighting, heating, and ventilation.
If you’re looking for a relatively hands-off option, open-air terrariums, like glass dishes or fish bowls (see right), are often easier to maintain than sealed versions, such as those in a bottle or a jar. Closed environments generally need more upkeep since the air can get polluted, moisture condensates more quickly, and plants might not get enough light.
Also on the low-maintenance front, desert or dry-land habitats like the one at right don’t require as detailed a substrate, or growing medium, as jungle and forests ecosystems do. (Cacti and succulents don't need intricate drainage systems.) For desert terrariums, a layer of sterile sand atop potting soil will work just fine. For other habitats, a more complex substrate is vital; more on that below. Let’s get started!
» Glass container, preferably with a wide mouth for easy construction
» Gravel, sand, or pebbles
» Activated (horticultural) charcoal
» Sterile potting mix
» Tiny plants
WHAT TO DO
1. Thoroughly clean your container.
2. Choose your plants. For ideas, check out this list of terrarium-friendly flora, with tips on growing conditions. Be sure to choose plants that have similar growing requirements, as they all have to get along and grow together in one tiny ecosystem.
NOTE: Steps 3 through 6 apply to jungle and forest plants. If you opt for a desert environment, you only need a layer of potting soil covered by a layer of sterile sand; install those, then skip to step 7.
3. Place at least 2 inches of gravel, sand, or pebbles—a.k.a. the drainage layer—at the bottom of your container.
4. Add ¼ inch to ½ inch of activated charcoal. This layer filters the air and keeps the environment clean (you can skip this step in open-top terrariums).
5. Next comes a blanket of sphagnum moss, which allows water to filter through to the pebble layer while keeping your soil in place.
6. Up next is a layer of sterile potting soil. You want fresh soil here, rather than reusing soil from old plants.
7. Remove your terrarium plants from their pots, gently tease the root bindings apart, and, if you wish to delay growth (a good idea for tiny environments with limited to no room to expand), prune the roots carefully. Gently add your plants to your terrarium.
8. For a finishing touch, decorate as desired with trinkets, seashells, rocks, or other ornaments. Stylish!
9. Water your plants as recommended; often a light misting from a spray bottle will do the trick.
10. Care for your terrarium as you would other houseplants: Prune damaged leaves, add water when the soil is dry, air out a closed terrarium once a month, and never add fertilizer, which encourages growth. In a terrarium, size is everything—and smaller is better!
SEE IT IN ACTION
More of a visual learner? The video below from Etsy.com’s How-Tuesday series walks you through the steps of creating a terrarium inside a light bulb.
FURTHER RESOURCES FROM HOMEGROWN AND BEYOND
• HOMEGROWN member Christine expounds on her love for terrariums in a recent blog post, and Cornelia shares links to funky mushrooms and more terrarium mossarium pandemonium.
• Speaking of, get the scoop on mossariums.
• For more on terrarium trends—unique containers, exotic plants, interesting ornamentation—check out Twig and The Hipster Home.
• Design Sponge offers a fun tutorial on sewing a terrarium.
• You might also consult The Fern and Mossery’s simple terrarium instructions.
• For more eye candy, there’s always Apartment Therapy.
• And from two ladies who know a thing or two about odes to the outdoors (“The terrariums are aliveeeee . . . !”): Watch Martha Stewart and Julie Andrews make a fairytale terrarium; Martha also demos how to make a woodland terrarium.
• Many of the photos in this 101 came from Joshleo's Terrarium set on Flickr—a gorgeous album worth a lengthy gander. (Warning: Hours of procrastination ahead.)
Got a terrarium conundrum—or a plant species to recommend? Post your comment below and keep the conversation rolling. For creating a covered environment on a much larger scale, you might be interested in the HOMEGROWN 101 on building a $30 hoop house; you can find more on hoop houses here. You might consider joining the Growing Indoors group, and you can always find more things to make, craft, plant, grow, cook, preserve, and pot in the HOMEGROWN 101 library.