A terrarium is a small indoor garden grown inside a clear glass container. It is an easy, beginner-friendly project that adds greenery to a desk, shelf, or windowsill—and it also makes a thoughtful handmade gift.
Choose either a closed terrarium for humidity-loving tropical plants or an open terrarium for plants that prefer drier air, such as succulents.
New to terrariums? Read Terrariums for Beginners: Everything you Need to Know for the basics, then return here for the complete tutorial.
Choose the Right Terrarium Style
A closed terrarium holds humidity, making it ideal for small ferns, moss, fittonia, and other tropical plants. An open terrarium has a wide opening and is better for succulents, cacti, air plants, and dry-climate plants because it allows more airflow.
Do not combine succulents with tropical terrarium plants: they need very different moisture levels. That is the most important decision to make before gathering materials.
Supplies Shopping List
For the most reliable result, buy supplies based on the kind of terrarium you are making: closed tropical or open succulent. Both need a clear container and drainage materials, but the soil and plants should not be interchangeable.
Plants in the same terrarium should have similar light and water needs.
Essential Supplies
- Clear glass container: Choose a wide-opening jar, fishbowl, cloche, or glass vase. A container with a lid is best for a humidity-loving tropical terrarium.
- Drainage material: Aquarium gravel, pea gravel, small river rocks, lava rock, or LECA clay balls. Plan for a layer about 1–2 inches deep.
- Activated horticultural charcoal: Use charcoal intended for gardening, aquariums, or terrariums—not barbecue briquettes. It is especially helpful in a closed terrarium.
- Barrier layer: Fine mesh, landscape fabric, a coffee filter, or sheet moss to keep soil from sinking into the gravel.
- Soil: Use a clean, well-draining potting mix for tropical plants; choose cactus and succulent mix for an open succulent terrarium.
- Planting tools: Long spoon, chopsticks, narrow trowel, scissors, and a soft paintbrush.
- Watering tool: Spray bottle, squeeze bottle, pipette, or turkey baster for controlled watering.
Optional Finishing Supplies
- Sheet moss or live moss for tropical designs
- Decorative gravel, sand, bark, or small stones
- Miniature figurines, tiny houses, mushrooms, benches, or fairy-garden accessories
- Small labels to identify plants and track planting dates
Plant Recommendations
Best Plants for a Closed Terrarium
Closed terrariums hold moisture and humidity, so choose compact, slow-growing plants that tolerate consistently lightly moist soil and indirect light. Ferns, pilea, peperomia, moss, and fittonia are widely recommended choices.
- Fittonia (nerve plant): Colorful veined leaves; stays relatively compact and appreciates humidity.
- Baby tears: A tiny-leaved trailing plant that creates a soft ground-cover effect.
- Miniature ferns: Look for button fern, lemon button fern, or other genuinely small varieties.
- Peperomia: Choose compact types with small leaves, such as trailing or dwarf varieties.
- Pilea: Small-leaved pilea varieties add texture and work well in humid arrangements.
- Selaginella (clubmoss): A fern-like plant that enjoys consistently humid conditions.
- Live moss: Works as a ground cover and gives the arrangement a woodland look.
Avoid fast-growing houseplants, since they will quickly crowd a small container.
Best Plants for an Open Terrarium
Open terrariums allow more air circulation. They are the better option for drought-tolerant plants, although a glass container without drainage still requires very careful watering.
Succulents generally need open containers, bright light, gritty soil, and time for the growing mix to dry.
- Haworthia: Compact, slow-growing, and typically more manageable than many larger succulents.
- Small echeveria: Rosette-shaped succulents that work well as a focal plant.
- Sedum: Small, colorful varieties can fill gaps and spill slightly over the soil surface.
- Crassula: Look for miniature jade types or other small varieties.
- Air plants: Display them above the soil or on decorative stones; do not bury their bases.
Do not mix these two groups. A fittonia needs moisture that can rot a haworthia, while the dry conditions that suit a succulent will stress tropical plants.
Materials and Tools
- Glass container, washed and completely dry
- Pebbles, aquarium gravel, or small river stones
- Activated horticultural charcoal
- Fine mesh, coffee filter, or sheet moss, optional
- Terrarium potting mix
- Small plants with matching light and water needs
- Long spoon, chopsticks, small trowel, or terrarium tools
- Small paintbrush for cleaning glass and leaves
- Spray bottle, squeeze bottle, or narrow-spout watering can
- Scissors for trimming roots or damaged leaves
- Optional decorative moss, rocks, bark, figurines, shells, or mini furniture
For tropical terrariums, use a light indoor potting mix. For open succulent terrariums, choose cactus and succulent soil mixed with extra perlite or pumice for faster drainage.
Step 1: Select and Prepare a Glass Container
Choose clear glass so light can reach the plants and so you can monitor moisture in the soil and drainage layer. A wide opening makes planting and maintenance much easier, especially for beginners.
Wash the container with warm soapy water, rinse it thoroughly, and let it dry completely. If the container previously held food, candles, or flowers, remove all residue before planting.
Avoid leaving soap, oil, or moisture inside because these can cloud the glass or affect the growing environment.
Step 2: Build the Drainage Layer
Add pebbles or gravel to the bottom of the container. This is called a false drainage layer because the water does not leave the container; instead, it collects below the soil where roots are less likely to sit in it.
Use a drainage layer around 1 inch deep in a small jar and 1 to 2 inches deep in a medium or large terrarium. Make the layer deeper if the container is tall or if it has a narrow opening that makes excess water difficult to remove.
Level the stones with a spoon. For a more natural look, create a gentle slope by making the pebble layer higher in the back and lower in the front.
Step 3: Add Activated Charcoal
Sprinkle a thin, even layer of activated charcoal over the gravel. In a terrarium, charcoal helps absorb some impurities and odors that can develop in the moist, enclosed container.
Use roughly 1 to 2 tablespoons in a small terrarium and increase the amount slightly for larger containers. Do not use charcoal briquettes for grilling; use activated charcoal sold for horticulture, aquariums, or terrariums.
Step 4: Separate the Gravel From Soil
Place a piece of fine mesh, coffee filter, or a thin layer of sheet moss over the charcoal. This optional layer helps prevent potting soil from washing down between the pebbles over time.
Trim the material so it fits inside the container without climbing up the glass. If you use sheet moss, keep it thin enough that it does not hold excessive water against the soil.
Step 5: Add the Correct Soil Depth
Spoon potting soil into the container, adding at least 2 to 3 inches for most small terrarium plants. The soil should be deep enough to hold the roots comfortably; plants planted too shallowly can become unstable and dry out quickly.
Make the soil deeper behind taller plants and slightly lower in front. Press it gently to remove large air pockets, but do not pack it tightly. Roots need loose soil to access air and water.
Step 6: Arrange the Plants Before Planting
Keep each plant in its nursery pot while testing the layout. Place taller plants at the back of a front-facing terrarium or in the center of a container that will be viewed from all sides. Put shorter plants and ground covers near the front.
Leave a small amount of open soil between plants. Crowded plants trap moisture, restrict airflow, and make it harder to remove dying leaves. Also leave room between foliage and the glass, particularly in closed terrariums where damp leaves against glass can rot.
Step 7: Remove Excess Nursery Soil
Take out one plant at a time and gently shake or loosen some of the nursery soil from its root ball. You do not need to bare-root the plant completely; remove only enough soil to make the root ball fit the terrarium.
Inspect the roots and trim any black, mushy, broken, or tightly circling roots with clean scissors. Remove yellow or damaged leaves now, because decaying plant material can mold inside a humid terrarium.
Step 8: Plant Each Terrarium Plant
Make a planting hole with a spoon, chopsticks, or a narrow trowel. Set the plant into the hole at the same depth it was growing in its pot, then gently pull soil around the roots.
Press the soil lightly around the plant base so it stands upright. Do not bury stems or cover the crown—the point where the stem meets the roots—because this can lead to rot.
Plant one variety at a time, checking the arrangement from the front after each plant. Use chopsticks to position plants in narrow containers and a soft paintbrush to sweep loose soil off leaves.
Step 9: Finish the Soil Surface
Level the visible soil and cover bare patches with sheet moss, preserved moss, fine gravel, bark, or decorative stones. Live moss is especially suitable for humid tropical terrariums, while dry stones and gravel are usually a better fit for open succulent terrariums.
Keep decorative material away from the base of each plant. Covering stems or crowns can trap moisture and increase the risk of rot.
Step 10: Add Miniature Decorations
Place figurines, small houses, tiny benches, mushrooms, or natural accents after the plants are secure. Press heavier decorations lightly into the soil so they do not shift.
Avoid decorating every empty area. Open space makes the terrarium look more realistic and gives you access for watering, trimming, and cleaning.
Step 11: Clean the Glass
Use a dry paintbrush to remove soil from the inside walls of the glass. Wipe the outside with a lint-free cloth. If soil sticks to the inside, use a barely damp paper towel wrapped around a chopstick, then dry the glass immediately.
Clean glass is not only decorative—it lets you notice mold, water buildup, pests, and soil dryness early.
Step 12: Water the Terrarium Correctly
Water slowly and conservatively. For a small tropical terrarium, begin with a few sprays or about 1 to 2 tablespoons of water placed directly onto the soil, not onto leaves.
For an open succulent terrarium, use a small amount of water around the roots, then wait until the soil has dried before watering again.
The soil should feel lightly moist for tropical plants, never soggy. A closed terrarium needs very little water because moisture evaporates, condenses on the glass, and returns to the soil.
An open terrarium dries more quickly but still needs careful watering because the container has no drainage hole.
If water collects above the gravel or pools at the bottom, remove it promptly with a turkey baster, pipette, paper towel wick, or by carefully tilting the container. Do not add more water until the soil has partly dried.
Step 13: Place It in Proper Light
Put the terrarium in bright, indirect light. A location near a window but out of direct sun is usually ideal. Direct sunlight can heat the glass quickly, especially in closed containers, and may burn leaves or overheat the plants.
Rotate an open terrarium occasionally if one side receives more light. Avoid dark corners, which can cause weak growth and keep soil damp for too long.
Step 14: Maintain Your Terrarium
Check the terrarium once a week at first. Look for condensation, yellow leaves, dry soil, pooling water, mold, or leaves touching the glass.
- Light condensation in a closed terrarium: Usually normal, especially in the morning.
- Heavy condensation all day: Open the lid or container for several hours to release moisture.
- Dry soil and no condensation for several days: Add a very small amount of water.
- Mold on soil or leaves: Remove affected material, wipe the glass, increase airflow, and reduce watering.
- Yellow or mushy leaves: Trim them away and check whether the soil is staying too wet.
- Plants outgrowing the container: Prune lightly or move the plant to a larger container.
Common Terrarium Mistakes
- Using a container that is too small for the plants’ mature size.
- Mixing plants with opposite moisture needs.
- Adding too much water because the container has no drainage hole.
- Keeping a closed terrarium in direct sunlight.
- Letting dead leaves remain inside the container.
- Packing soil too tightly around roots.
- Planting foliage directly against the glass.
- Treating charcoal as a replacement for proper watering and airflow.
A terrarium is a living project, so a few small adjustments are completely normal. Start with plants that need similar conditions, avoid overwatering, and give your mini garden bright, indirect light.
After you’ve built your terrarium, keep it thriving by steering clear of the 10 Terrarium Mistakes Beginners Should Avoid.
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