Introduction: How to Make a Terrarium

About: I've worked for Instructables off and on since 2006 building and documenting just about everything I enjoy doing. I am now the Creative Programs founder and manager for Autodesk and just finished building out…

This DIY Terrarium makes a great gift, can be assembled in a matter of minutes and looks really beautiful. Glass globes are now readily available at garden nurseries, and air plants like the Tilandsia that we used in this terrarium are even carried at Home Depot during some seasons. I think at one point air plants were harder to locate, but now they're becoming quite common. Terrariums are simple to make and maintain, and are perfect for hanging next to a desk, bed, or by the kitchen window where they can be admired and enjoyed.

The terrarium in the picture above was a gift that my sister and I made to give to my mom for her birthday. Although she's excellent at taking care of living things, like her children, she's got a pretty rough track record when it comes to plants and things. We thought that because of its small size, and simple maintenance requirements, a terrarium might fair a bit better.

Keep reading to find out how to make your own terrarium at home!

Step 1: What You'll Need to Make a Terrarium

The materials for a terrarium can usually be purchased at a local nursery or hardware store. There are online retailers for most of these items, and specialty retailers like Paxton Gate in San Francisco who specialize in exactly these kinds of supplies.

To make a terrarium you will need:

  • Glass globe to house the terrarium - this can be purchased new or a repurposed glass jar or bowl that has a pleasing volume
  • Sand
  • Activated charcoal
  • Well draining potting soil (cactus & succulent soil can be a good choice here)
  • Various mosses
  • Small sticks or bark
  • Minerals, shells, or stones
  • Small plants well suited terrarium life
  • Air plant like tilandsia, or another bromeliad you like
  • Succulents, if you like, although, it's not recommended to mix succulents and plants due to different watering requirements - we did anyway
  • A nice hook or string to hang it by
  • Spray bottle or mister

Step 2: Adding the Sand Layer to the Terrarium

The bottom layer in the terrarium is a thin layer of sand or pebbles for drainage. We chose sand because Long Island (where the terrarium was constructed) is literally one giant pile of sand, so if you dig down a bit, it's readily available and free. Small pebbles might look nicer.

Find a small cup, scooper or funnel to load the sand into the terrarium. It doesn't take much, 1 cup of sand is probably more than enough.

Step 3: Adding an Activated Charcoal Layer to the Terrarium

The next layer to put in the terrarium is activated charcoal or activated carbon - same thing. This is the stuff from your Brita water filter or fish tank filter - if you've got that, toss it in there. Otherwise, you can buy small amounts online, or skip this step entirely. I just happened to have a whole lot of activated charcoal lying around for a future project so we took a 1/4 cup or so and added it in.

My sister and I devised a simple cardboard chute to deliver materials precisely where we wanted them in the terrarium. The chute, plus a push stick or brush works much better than the dump method.

The activated charcoal layer just keeps things "fresh", or so I've read.

Step 4: Adding the Terrarium's Soil Layer

Next, add an inch or two of well draining soil. I mixed some potting soil with succulent soil to achieve a good blend. You don't need much, as the plants themselves come with a soil clump that will likely allow them to survive on their own for quite a while.

We found the paintbrush to be very helpful in moving the soil around. If you were making a larger terrarium, or working with one that had a larger hole, I think positioning plants and soil mediums would be much easier, but alas, we liked the look of this globe and did our best.

Step 5: Adding Larger Features to the Terrarium

We're breaking a cardinal rule here of terrarium building and including both a plant and a succulent in the same terrarium. Generally it's thought that the small plants well suited to life in a terrarium require different living conditions than succulents. I however am a non-conformist and chose to break this rule.

The living plant we chose was hearty and strategically planted at the back of the terrarium where it's likely to remain moister. We positioned the succulent on a little hill of soil so it would drain first, as well as located it closer to the opening which is likely to be a dryer environment. I'm sure it won't take too long for terrarium experts to correct my potentially fatal mistake, however, we really wanted to combine both plants and succulents in a single terrarium.

It can be easier to position the plants before filling the terrarium with soil, and then backfill the space between the root balls of the plants. You can also simply dig small holes and plant normally. Both methods worked well for us, but the bigger the plant, the more sense it makes to put it in before the soil, and then add the soil around it.

Don't overcrowd the terrarium with large elements! There's quite a few additional small elements that we're adding, so it's important to leave yourself some room to be creative with what little space remains.

Step 6: How to Add Small Features to a Terrarium

We used a pair of long handled tweezers to position additional items inside the terrarium. Chopsticks also work well.

We added in a hearty dose of a few different types of dried, ornamental mosses, a mineral that my mom really likes, and a small stone egg. (My mom has a PhD in Pre and Perinatal Psychology, what can I say, she's really into eggs.)

We also included some dried pieces of tree bark from some trees that were shedding this past fall in Oakland. This was followed up by inserting a small air plant called Tilandsia. These plants don't need to be planted in the conventional sense - they require no soil and simply extract their nutrients and water from the air. They are perfect candidates for terrariums.

Finally, we added in some colorful shells that we had collected at the beach (wash them thoroughly as they may introduce salt to the tiny ecosystem, and plants and salt don't get along well) and a small little set of thorns that had come off of a cactus that I used to own, but died.

Step 7: Terrarium Accessories and Maintenance

It can be helpful to buy a few accessories for the terrarium. If you've made a glass terrarium in a globe that isn't self supporting, you'll need some kind of a hook. I think these iron hooks look quite nice when paired with the terrarium. We bought one off of amazon.com for a few bucks.

You've also got to water the terrarium from time to time. Maybe once or twice a week depending on location and weather conditions. We set my mom up with a dual watering system - the regular water can that services most regular house plants, and then a special mister that's designed to spray down living things like the air plant. A regular spray bottle from the drug store will work just fine, we just wanted to class the gift up a bit.

Maintenance on these little guys is pretty easy. Simply hang it in an area that receives moderate sun (but not direct sun if possible) and make sure you water the little guys once a week or so. If it's looking real wet in there, or if mold or a swampy odor develops, you're definitely over-watering. If the plant parts start to wilt, they you're likely under watering.

I'm looking forward to making a bunch more of these in the future out of reclaimed cool looking glass volumes. I'll be keeping my eyes open for this kind of stuff at yard sales from now on.

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