Terrarium Workshop Singapore Blog

Guide to Building a Closed Terrarium in Singapore [2024]

Closed Terrarium Singapore

Closed Terrarium Singapore
Closed Terrarium Singapore

Closed terrariums are miniature, self-sustaining ecological systems, boxed into a glass container.

A truly closed terrarium is a charming diorama of nature, an often-isolated, quiet space to house where plants grow, a nurturing, green escape.

The benefits of creating and owning a closed terrarium in a city like Singapore are manifold: from the beauty they bring into your life to the small astronaut ecologists they make out of its keeper.

In this guide, you will learn how a closed terrarium works, and be shown, step-by-step, how to create your own or you can try a terrarium workshops.

What is a Closed Terrarium?

A closed terrarium is a sealed glass vessel that houses various plants and soil pretty much like a typical planter but with an added humid condition inside the glass container or glass jar as it is closed.

In contrast with an open terrarium which allows the air to circulate while a closed terrarium does not as it is closed, the escaped water from a closed terrarium can be recycled by these plants through condensation and evaporation as it promotes water loss from the open or terrarium interior.

Because of this condition, a lot of plants prefer closed terrariums such as mosses, ferns, and other tropical plants that prefer high humidity to grow well compared with those plants that grow in and prefer higher light conditions to grow.

How Do Closed Terrariums Work?

The terrarium, a confined environment, has water circulate differently. Water vapour rising from the surface of the water cycle plants’ transpiration condenses on the terrarium container’s walls and runs back down to the soil. There is no need for external watering.

The light that penetrates the glass container is utilized by the plants in photosynthesis to produce oxygen which recirculates with other gasses through the water cycle of the open terrariums.

And so everything maintains itself and a harmonious balance. Light, high humid environment high humidity, water, and air circulation make or break your terrarium.

Choosing the Right Plants

Selecting the right plants is essential for a thriving closed terrarium. Ideal plants include:

  • Mosses: These are excellent for ground cover and add a lush, green look.
  • Ferns: Their delicate fronds add texture and height.
  • Tropical plants: Small versions of plants like Fittonia, Peperomia, and Pilea work well.

When selecting plants, note that you need to think about their light, heat, and humidity requirements. Plants that prefer similar conditions are more likely to succeed in a closed terrarium together.

Materials Needed

To build a closed terrarium, you’ll need the following materials:

  • Glass container: buy a glass container with a lid clear aquarium or fish bowl is good. You can also get glass jars or a container made specifically for terrariums.
  • Soil: Use a well-draining potting mix suitable for the chosen plants.
  • Activated charcoal: This helps to filter the air and water inside the terrarium.
  • Pebbles or gravel: For drainage at the bottom of the container.
  • Decorative items: Such as small figurines, rocks, or pieces of driftwood.

Most of the materials are listed below if you are planning to buy a plant or a DIY kit, and are available from your local garden centre, craft store, or online in Singapore.

Step-by-Step Guide to Building a Closed Terrarium


  • Clean your container thoroughly to prevent mold and algae growth.
  • Add some stones or gravel at the bottom as drainage.
  • Keep the area ventilated by scattering an inch or so of activated charcoal on the pebbles.
  • Finally, top that with potting soil as deep as necessary to allow the roots of your plants.


  • Dig in little holes in the soil, and pop the biggest veggies in first, filling all the gaps with the smaller ones.
  • Firmly press the soil around the roots to ensure they are well-secured.
  • Arrange decorative items to enhance the aesthetic appeal of your terrarium.

Finishing Touches

  • Lightly water the plants to help them settle in. Avoid overwatering.
  • Seal the terrarium with the lid to create a closed environment.
  • Place the terrarium in an area that receives indirect light. Do not place it near a window where sunlight strikes it directly since that will overheat it.

Maintenance and Care

Although closed terrariums are low maintenance, they do require some care, below is the care instructions:

  • Moisture: Check the soil for moisture. If condensation ceases, the device can benefit from a bit of watering.
  • Light: Particularly important for the plants that will occupy your terrarium, the story goes, so ensure that it gets indirect light. Plant life needs air and light to thrive. Too little and they fail to grow; too much and they shrivel.
  • Prune: When needed, cut back on abundance and trim any dead leaves.
  • Cleaning: Wipe the inside of the glass if algae or mold develops.

Mistakes to Avoid

  • Overwatering: This is probably the most common mistake and results in mold and root rot.
  • Inappropriate plant selection: placing plants with incompatible humidity and light requirements next to one another can lead to the death of at least one of them.
  • Improper Light Exposure: The terrarium tends to overheat when there is too much direct sunlight and too little when there is not much.

Closed Terrarium Singapore

Making a closed terrarium in Singapore is so much more than just another plant. With an understanding of the concept, a knowledge of suitable plants, and some know-how, an artificial ‘container garden’ that is merely decoration can become a miniature world that, with minimal care and a little know-how, needs very little effort. With a lot of patience and a little creativity, you can have a unique little digital pet or showpiece.

Frequently Asked Questions (FAQs)

If you have any questions about Closed Terrarium Singapore, you can refer to the frequently asked questions (FAQ) below:

How often should I water my closed terrarium?

Typically, closed terrariums rarely need watering. Check moisture levels and only add water if moisture level or condensation is absent.

What if my terrarium gets moldy?

Remove affected plants and reduce watering. Ensure excess water in the container is clean and receiving proper light.

Can I use any type of soil?

It’s best to use a well-draining potting mix designed for the specific plants you are using.