Make your own terrarium

How to make your own terrarium

A terrarium is a fantastic low maintenance piece that adds an element of interest to your home. Terrariums are generally closed miniature ecosystems with daily cycles, where you can see the regular build up and removal of condensation on the inner part of the glass. Many think that they are hard to make but with a few things you can easily make your very own closed ecosystem! This makes terrariums a perfect gift for your friend or family member.

What you will need:

[what each component does is highlighted in bracets]

  1. Telescopic small trowel and fork; optional cork dibber

  2. Gloves and mat/cover

  3. Glass jar with natural cork top [helps air circulation in jar]

  4. Pebbles, building gravel or clay balls [drainage]

  5. Soil with a mixture of coir and perlite [growing medium with extra drainage]

  6. Activate charcoal [keeps terrarium free of bad bacteria and fungi]

  7. Sphagnum moss [helps regulate moisture levels]

  8. Garden moss

  9. Small humid-loving houseplants

Large terrarium with new plants

You can purchase any of the above from any good garden centre, houseplant shop or local retailer like eBay or Etsy, either as a sole purchase or set.

Ideal houseplants for terrariums

(in order of popularity)

Idea plants for a terrarium, the nerve plant
  1. Nerve Plant or Fittonia

  2. Asparagus Fern or Asparagus setaceus

  3. Polka Dot Plant or Hypoestes phyllostachya

  4. Ferns such as Maidenhair (Adiantum), Birds Nest (Asplenium nidus) and the Button Ferns (Pellaea rotundifolia)

  5. Aluminium Plant or Pilea cadierei

  6. Carnivorous plants such as the Pitcher Plant (Nepenthes), Venus Fly Trap (Dionaea muscipula) or Sundew Plant (Drosera)

  7. Baby Tears or Soleirolia soleirolii

  8. Creeping Fig or Ficus primula

  9. Air Plants or Tillandsia

… and many more.


  1. Clean glass jar using washing up liquid, ensure all soapsuds have been completely removed. Alternatively you can use rubbing alcohol in tissue to clean the jar. Do not use bleach-base products.

  2. Clean gravel by flooding it with tap water in a sink. Keep washing until water turns clear.

  3. When making the terrarium use gloves, similar to marigolds. If you cannot wear gloves (or don't have them) then use rubbing alcohol on your hands to prevent contamination.

  4. Do not make your terrarium outside to prevent contamination.

Making your terrarium

Place gravel in bottom of jar

1 Place enough gravel (or clay balls) at the bottom of your jar to fill 10% of the volume.

Add spagnum moss onto gravel

2 Place a thin layer of sphagnum moss onto the gravel, flatten as much as possible.

Sprinkle activated charcoal onto sphagnum moss

3 Sprinkle the active charcoal over the sphagnum moss.

Add soil mixture onto Sphagnum moss and activated charcoal layer

4 Fill the jar with soil mixture no more than 25% of total volume including steps 1-3. Ensure that the soil mixture is evenly spread out.

Make small dents in the soil to plant your plants

5 Make small dents into the soil in order to plant your plants.

Place your plants along with any decoration into your terrarium

6 Place moss on top of the soil and add any additional decorative items if wanted such as bark, grit, small ornament, stones or piece of driftwood.

Start to slowly water your terrarium

7 Slowly water your terrarium (do not overwater) until you notice that the soil starts to turn blackish brown and the sphagnum moss starts to swell. Only use filtered water. Give a quick mist or spritz and close the lid.

You may need to top up moisture levels in your terrarium

8 Your plants will take some time to start to root. Regularly check your terrarium (monthly) to ensure that the plants are growing well.

Label the bottom of your terrarium, when closed for the last time with a date so in time you can work how long it has been closed off to the world.

After care of your terrarium

Looking after your terrarium
  1. If you notice that your plants have started to wilt or the soil looks dry, open the lid and give a little extra water. You should only need to reopen your terrarium once or twice. If a little water is required, mist or spritz the inside.

  2. If you have overwatered your terrarium, you will notice a constant amount of condensation on the inside of the glass. To help remove this water, leave the lid open for a few days until excess water has evaporated.

  3. Place your terrarium in a place with indirect sunlight. Do not place it too bright in place as the glass will magnify the light and burn your plants. If you notice that your plants have started to scorch, move to a darker area of your home. Your terrarium will look unhealthy for some time or you may need to reopen and replace the plants.

  4. Terrariums can survive under artificial horticultural lights (purple ones).

  5. Most people leave terrariums as a closed ecosystem and you will start to notice some plants die, others takeover etc.

Other kinds of terrariums

An example of an open terrarium

Open terrariums

  • These terrariums have one side of the container open to the environment.

  • The key difference between closed and open is that the open terrariums require more maintenance. They will need regular watering and trimming to prevent plants from growing out of the container.

  • These kinds of terrarium can be placed in lighter areas of your home compared to closed terrariums, just make sure that the open part is facing the light.

  • To make this kind of terrarium simply follow the above instructions.

An example of a dry terrarium with desert plants

Dry terrariums

  • These kinds of terrarium are open and are filled with succulents and/or cacti. These terrariums can be placed in bright areas, and typically have their soil covered with stones or some sort of grit.

  • To make a dry terrarium follow the above instructions but hold off on the watering. Only use a pipette or teaspoon to water after putting your terrarium together, one to two drops or teaspoons per plant should suffice.

  • Water terrarium using one to two drops or teaspoons every month during spring to late-autumn.

  • If your plants start to look mushy then you are overwatering these plants. Stop watering. It may be too late and your plants may need to be replaced. If you start to notice a mottled pattern on your succulents or cacti then give them water – this is a sign of underwatering.

  • Keep these dry terrariums out of humid areas of your home. These kinds of plants do not like humidity so cannot be placed in closed terrariums.

Moss Balls or Marimo in a glass tank

Water terrariums

  • These terrariums contain plants that have their roots submerged in water. Typically enclosed by a corked container (can also be grown in a fish tank), they regularly require their water to be replaced to prevent bacterial or fungal build up.

  • Some examples of water terrariums include Moss Balls or Marimo, native to the lakes of Japan; offers good luck to a home. Though these balls of green look like moss they are in fact a type of algae.

Sometimes animals such as lizzards and fish can be added to terrariums, with some modifications, to make vivariums and aquariums. Vivariums being suited to reptiles and amphibians, and aquariums being for fish. More information can be found online as further discussion is out of the scope of this guide.

If buying a terrarium, things to look out for

  1. Soil substrate should not fill more than a third of the terrarium.

  2. If looking for closed terrariums do not touch ones with loosely fitting lids.

  3. If plants are not planted and can move around the terrarium, then you should not buy it.

  4. Check plants to see if they are healthy and are not brown or have brown blotches or are wilting.

  5. Do not buy terrariums with too much condensation on the inner part of the glass.

Terrariums of various sizes on tray

If you have any questions or issues you can get in touch via the contact form.