How to Set Up an Indoor Terrarium in Ten Easy Steps

It’s possible to make terrariums from a variety of plants and container styles. There’s no limit to how creative you can be, but following these steps will ensure you get the right start.

If you love the idea of gardening but don’t have much of a green thumb, then an indoor terrarium may offer the perfect solution. These small-scale setups make it possible to enjoy a variety of houseplants within a cute space that’s easy to customize.

While a well-established terrarium may look intimidating, they are surprisingly easy to put together. Here’s are ten steps to help you put together the perfect terrarium.

1. Choose the Best Plants

The success of your terrarium depends on choosing the right plants to put within it. Look for species that can tolerate humidity, such as African violets, baby’s tears, spider fern, creeping figs, guppy plants, earth stars, and most varieties of mosses.

Ideally, you want small, slow-growing plants that won’t overcrowd the terrarium. If you’re using an open container, then it’s possible to add cacti and succulents to the growing space.

2. Gather Supplies

Grab the right tools before assembling your terrarium. Here’s what you need:

Note: Glass is the popular option but plastic tends to be lighter and more durable

3. Build the Foundation

The first assembly step for a DIY terrarium is to place about two inches (5 cm) of charcoal at the base of the container. This promotes drainage, so roots don’t get too damp while removing toxins and odors from the container. You can top this with a layer of rocks or aquarium gravel.

4. Combine The Components and Build a Second Layer

Combine more charcoal with your soil and blend them. Add this mixture to the container until it’s between one-fourth and one-third full.

5. Add Plants and More Soil

Remove your plants from their containers and position them in the terrarium on top of the soil. Make sure there’s enough room between each one for extra soil. Gently pack in a few more handfuls around the plants until they are secured.

6. Press Out Any Air Pockets

Using your fingers, press around each plant until you pack the soil in and around the plants and remove any air pockets. You can gently tap the terrarium on a hard surface until the soil settles.

7. Top Dress with Moss and Décor

Once your plants are in place, it’s time to position moss on top of the soil. The moss works to absorb excess moisture and minimize odors while pulling different design elements together for a lush look. If desired, you can also add non-living decorations within the terrarium, such as rocks, structures, or small figurines. This is the stage to be creative, so don’t limit yourself.

Pay attention to how the terrarium will look from different perspectives. You’ll want to set up the design differently if it will be visible from all sides instead of just one angle.

8. Add Water

It’s now time to water everything in place. Use a watering can to gently moisten the soil, stopping once it feels wet to the touch. The amount of watering necessary going forward depends on your setup. Plants in a closed terrarium need less frequent watering than those with an open top. Always test the soil for moisture before adding more water.

It’s also a good idea to lightly mist your terrarium plants every few days to keep them hydrated.

9. Place Under Indirect Light

Think carefully about your terrarium’s location. While the plants need light to survive, putting them under direct sunlight can quickly cook them because the glass will magnify the light’s intensity. For this reason, it’s best to be cautious about putting your plants under a south or east-facing window.

Ideally, a terrarium should be placed where condensation collects on the glass sides. If this doesn’t happen, you need either more water or more light exposure.

10. Perform Maintenance as Necessary

Once established, terrariums require minimal maintenance. You may need to trim off the leggy stems of some plants and remove any dead leaves and other debris, so they don’t lead to fungal or bacterial infections. The moss requires occasional trimming to keep its length under control.

If you have a closed terrarium, it’s essential to ventilate it for a few hours every two weeks. This allows stale air to escape to keep things fresh. 

Setting up a terrarium takes time, but doing it right will reward you with healthy plants and a beautiful display. Just be warned—you’ll likely find that setting up an indoor terrarium is addicting and may soon find yourself with more than you anticipated.