DIY Closed Terrarium: How to Create Your Own Bottle Garden

This guide focuses on closed terrariums, which function as miniature greenhouses, requiring minimal upkeep while creating a thriving natural display. Read on to learn how to build your very own self-sustaining bottle garden.

Materials Needed for a Bottle Garden

Small stones or pebbles for drainage

Activated charcoal

Nutrient-rich potting mix

Small plants that thrive in high humidity

Springtails (optional, for natural maintenance)

Preserved mosses

A glass container with a lid (repurpose a jar or find a vintage one at a thrift shop)

A substrate barrier or sphagnum moss

Best Plants for a Closed Terrarium

For an enclosed environment, choose plants that thrive in high humidity, such as ferns, calathea, and peperomia. These species adapt well to the greenhouse-like conditions inside a sealed container.

Slow-growing plants work best to prevent overcrowding, so consider options like nerve plants (Fittonia), peperomia, and live mosses. Avoid succulents, cacti, and air plants, as they require drier conditions and good airflow.

Recommended plants for closed terrariums:

Maidenhair Fern

Tradescantia varieties

Creeping Fig

Ivy

Nerve Plants (Fittonia)

Peperomia

Step-by-Step Guide to Creating a Bottle Garden

1. Create a Drainage Layer (False Bottom)

A proper drainage layer is essential for excess water management, preventing root rot.

Start by adding a layer of small stones or pebbles at the bottom of your glass container. This allows excess water to collect away from plant roots, reducing the risk of overwatering. If you tend to water generously, this step is crucial.

For added aesthetics, consider using a thin layer of decorative pumice followed by a thicker layer of lava rocks.

2. Add a Separation Layer

To prevent plant roots from growing into the drainage layer, add a barrier between the stones and the soil.

A separation layer ensures longevity by keeping roots from reaching the water reservoir. Use a mesh screen, a substrate barrier, or a layer of sphagnum moss. Simply place the barrier inside, allowing it to expand as it settles into the bottle.

3. Add Activated Charcoal

This step is essential for maintaining a healthy environment inside your terrarium.

Activated charcoal helps filter toxins, absorb odors, and prevent mold growth within the sealed container. A thin layer of charcoal between the drainage and soil layers will ensure a fresher, longer-lasting terrarium.

4. Introduce Decomposers (Optional)

To naturally manage mold and decay, consider adding springtails.

Springtails are tiny beneficial insects that feed on mold and organic debris, acting as a built-in cleanup crew for your terrarium. While optional, they help maintain balance within your ecosystem.

5. Add the Potting Mix

Use a nutrient-rich, well-draining potting mix to support plant growth.

Choose a soil blend with organic compost for optimal plant nutrition. Coco coir can also be a great addition. Generally, the soil layer should be about twice as thick as the drainage layer, but adjust depending on your container’s size.

Pro tip: Pre-moisten the soil before adding it to help plants establish quickly.

6. Plant Your Greenery

Select plants that fit through the bottle’s opening and carefully place them inside.

Here are some ways to position plants in a bottle garden:

Use long tweezers to place individual cuttings

Tie plants to a string and gently lower them into position

Drop them in and use tools to adjust their placement

Smaller plant cuttings with well-developed root systems work best. Water-propagated plants adapt quickly since they are accustomed to high-moisture conditions.

Worried about plant placement? Don’t stress! Unlike traditional gardening, bottle gardens allow nature to take its course. Simply arrange your plants and let them settle naturally.

7. Add Mosses and Decorative Elements

Enhance your terrarium’s aesthetic with natural touches.

Layer in preserved moss, decorative stones, driftwood, or other natural elements to complete the look. Rather than precisely arranging each piece, drop them in and let nature shape the final design.

8. Water and Seal Your Bottle Garden

Once satisfied with the arrangement, hydrate the terrarium and seal it.

Use filtered water and distribute it evenly—using a turkey baster can help direct water along the container walls. This also helps clean dust from the glass.

Caring for Your Closed Terrarium

Now that your bottle garden is complete, sit back and let it maintain itself!

For best results:

Place the terrarium in indirect sunlight

If sealed properly, the water cycle will sustain the plants without additional watering

After watering, moisture will evaporate, condense on the glass, and drip back into the soil, maintaining a continuous cycle

If plants outgrow the space, trim them with sterilized scissors

Occasionally open the container to refresh the air, if needed

Remove any dead plant material using long tweezers

If mold appears, consider adding decomposers like springtails

Final Thoughts

We hope this guide inspires you to create your own closed terrarium! A bottle garden makes a beautiful centerpiece, a unique bookshelf accent, or a natural display for any space. The most stunning terrariums mimic real landscapes, incorporating native plants and natural elements.

No need for expensive materials—step outside and find inspiration in the natural world around you.

Happy growing!