First things first – Monitoring and Adjustments

You have just finished building your terrarium, what now? The first few days are an important time for the plants and moss to adjust to their new environment. The main things you should do during this time are:

  • Keep the terrarium at comfortable room temperature – at least 16°C
  • The terrarium should be in a bright spot
  • Monitor water and moisture levels
  • Check for any mould developing or plants dying

It takes anything from a week to a couple of months for your terrarium to fully settle and during this time a lot can happen and change. Sometimes your terrarium thrives from day one, other times you may have to make a few adjustments to create the happiest environment for your plants and moss.

If you have bought a terrarium from us, it is unlikely you will need to make any changes as we carry out this monitoring procedure before putting our terrariums up for sale.

What to Avoid

  • Direct sunlight and direct heat – such as directly above a heater.
  • Overwatering – the key is to keep the terrarium moist but not soggy wet.
  • Spraying the plant leaves – Add water by spraying against the terrarium walls. Wet leaves can become infected in this humid environment.

What we want to see

You will see water on the sides of the terrarium most of the time but depending on the time of day this will change.

Our goal is to see more water drops in the evening and night time when plants produce oxygen and the humidity rises. During the day you will also see some water on the walls but not as much.

If there is so much water on the walls that you can barely see inside then the terrarium has been overwatered. Stop watering for some time and try moving the terrarium into a warmer location to accelerate the process of absorbing the excess water.


As with all things live plants, there are many kinds of problems that can arise with your terrarium. Here, we have listed some common issues and our recommendations for how to deal with them.


One of the most common issues is mould. This usually appears on wood but can also happen to plants or moss. Mould usually develops due to poor air circulation, too much heat and too high a humidity. It can even be introduced by spores floating into the terrarium from an external source.

Use a cotton bud soaked with some alcohol to remove mould from non live items such as rocks, the glass or wood.

Use a cotton bud without any added alcohol on your live items – the moss and plants. Also remove any damaged leaves.

Cleaning the mould, removing dead plants/moss and decreasing the temperature should help resolve this problem.


If you notice white or yellow egg looking things in the soil then it is most likely fungus. This won’t harm the plants and in fact has some beneficial properties – but it is worth a try for us to control it so it does not take over the soil entirely.

To fix this issue, simply lift or remove the rocks and moss above the fungus ridden parts of the soil, scoop it out and replace it with some fresh soil mix.

Mushrooms may grow in the terrarium too, they should not cause any issues – you can let them grow or remove them as you please.

Bad Smell

If you notice a nasty stench eminating from your terrarium then this is quite a bad sign. It is likely it has been left too long with too much watering and humidity and has caused rot.

Try removing any dead components and moving the terrarium somewhere warmer. Stop watering it and monitor it daily.


The most common terrarium pest in our experience is fungus gnats. To break the life cycle of these little nuisances we keep some carnivorous plants near the terrarium.

It is possible to get any other plant pests in a terrarium just as they could happen without one. We recommend you use the same treatment methods as your normally would.

Plants growing too much

What a great problem to have! This means your plants love the environment you have created for them. You can choose to cut them back to maintain your design or let them grow free and wild.

Pale or Dry looking plants

The plants are thirsty, give them a drink!

Brown Moss

This can be both a sign of underwatering or overwatering. The best way to check this is by touch, if the moss is crispy then it needs some water to soak up. If it is soggy then you need to reduce watering of the terrarium and check it daily to make sure it dries out a little bit.

Leggy Plants

If the plants grow long, but with few or no leaves, are bending in odd directions and showing less colour then they are probably craving more sunlight. Find a brighter spot for them and they should recover.

Annual Care

At least once a year, check over your terrarium and clear out dead leaves and remove anything that looks dead or particularly unwell. You can also use this time to clean up your decorations such as wood, stones or ornaments.

Use a sponge on a stick or something similar to clean the glass, especially if it is growing algae.