Can You Grow a Bonsai in a Terrarium? A Guide to Bonsai Terrariums
A bonsai under glass looks like a tiny forest frozen in time: a sculptural little tree, cushions of moss and a few ferns, all sealed in a jar. It is one of the most striking terrariums you can make. But can a bonsai really live in a closed terrarium, and how do you keep it happy?
The short answer is yes, if you choose the right tree. Here is what works, what does not, and how we care for the bonsai terrariums we make in our London studio.
Can You Put a Bonsai Tree in a Terrarium?
Yes, but not every bonsai. Many classic bonsai trees, such as junipers, pines and maples, are outdoor trees. They need fresh air, cold winters and a seasonal rest, so a warm, humid, closed jar would slowly weaken them.
Tropical trees are a different story. They are used to warm, humid conditions and steady temperatures, which is exactly what a closed terrarium provides. The most popular choice, and the one we use in our kits, is the Ficus Ginseng.
A Ficus Ginseng bonsai in our 'Seattle' terrarium.
Why Ficus Ginseng Works So Well
- It enjoys humidity. Ficus Ginseng is a tropical fig, so the moist air inside a closed jar suits it.
- It copes with indoor light. It grows happily in bright, indirect light rather than needing full sun.
- It grows slowly in a jar. In a terrarium it stays compact, and a light trim now and then keeps its shape.
- It has character. Its thick, curving roots and small glossy leaves give that classic bonsai look, even at a small size.
Is Ficus Ginseng a real bonsai?
Bonsai is a way of growing and shaping a tree in a small container, rather than a type of plant. Ficus Ginseng (a form of Ficus microcarpa) is one of the most common indoor bonsai, loved for its swollen roots and easy care. So yes, it is a bonsai, and one of the best suited to life indoors.
DIY bonsai terrarium kits and ready-made bonsai terrariums, from compact 21 cm jars to 45 cm statement pieces.
How to Care for a Bonsai Terrarium
Bonsai terrariums need very little care, but a few habits make a big difference.
Keep the lid closed
The lid is what creates the humid mini climate the bonsai enjoys. Keep it closed. Only take it off for a short while if the terrarium looks very wet, or if the glass stays heavily misted all day, every day, for several days in a row.
Water a little, but do not forget to water
A closed terrarium recycles its moisture, so it needs far less water than a potted plant. However, it still needs some. The most common reason a bonsai terrarium struggles is not too much water, but soil that has been left to dry out.
Check it every couple of weeks. If you see no condensation on the glass for several days and the soil or moss looks dry and pale, add a small amount of water around the base of the plants. Our guide on how to water a closed terrarium explains what healthy condensation looks like.
Give it bright, indirect light
Place your terrarium in a bright spot away from direct sun. Sunlight through glass can overheat a closed jar very quickly. Keep it away from radiators too. If your room is dark in winter, a terrarium grow light helps. See where to place a closed terrarium for more ideas.
Our ready-made 'Tokyo' bonsai terrarium in a bright spot, out of direct sun.
Trim it now and then
Once your bonsai grows a little, snip back long new shoots to keep its shape and stop leaves pressing against the glass. Remove any fallen leaves so they do not encourage mould.
Common Problems and Simple Fixes
- Dry soil and no condensation: the terrarium needs a little water. Add a small amount and check again in a few days.
- Glass misted all day, every day: it is too wet. Take the lid off for a few hours, then close it again.
- Dropping leaves: Ficus often drops a few leaves after being moved or when its light changes. Keep it in one bright spot and it usually settles.
- White fuzz on soil or wood: this is usually mould from too much moisture. Remove it and air the jar briefly. Our guide to mould in terrariums covers this in detail.
- Tree touching the lid or glass: trim the tallest shoots.
Choosing a Bonsai Terrarium
You can build your own or choose one that is ready to display. Here are a few options from our bonsai terrarium collection:
DIY bonsai terrarium kits
- 'Kyoto' and 'Sapporo': compact 21 cm kits, a great first bonsai terrarium.
- 'Perth': a 25 cm bonsai terrarium kit and one of our most popular.
- 'Grand Canyon': a 23 cm bonsai terrarium kit, also available ready planted.
- 'Portland': a round globe jar with the bonsai at its centre.
- 'Kuala Lumpur': a 32 cm jar with more room for a layered landscape.
- 'Siena' and 'Lake District': 45 cm statement pieces for a table or hallway.
Our kits include the glass, the bonsai, moss and the layers you need, with a step-by-step guide.
The 'Grand Canyon' bonsai terrarium, available as a DIY kit or ready planted.
Ready-made bonsai terrariums
If you would rather enjoy it than build it, our 'Tokyo' and 'Geneva' terrariums are planted by our team and arrive fully assembled.
A 30 cm bonsai terrarium, planted by our team and delivered fully assembled across the UK.
How to Make Your Own Bonsai Terrarium
Already have a jar? You can add a young Ficus Ginseng to your own closed terrarium. Choose a jar with enough height for the tree to grow a little, build the usual layers (drainage, activated charcoal, soil), plant the bonsai first as your focal point, then add moss and smaller plants around it. Our step-by-step terrarium guide walks you through each layer.
Young Ficus Ginseng plants in several sizes, ideal for adding a bonsai to your own terrarium jar.
FAQs
Can a bonsai live in a closed terrarium?
Yes, if it is a tropical bonsai such as Ficus Ginseng. Outdoor bonsai like junipers, pines and maples are not suitable for a closed jar.
Should a bonsai terrarium be open or closed?
We recommend keeping a Ficus Ginseng terrarium closed. Only open it briefly if it becomes very wet or the glass stays heavily misted all the time.
How often should I water a bonsai terrarium?
Rarely, but not never. Check it every couple of weeks and add a small amount of water when there has been no condensation for several days and the soil looks dry.
Why is my bonsai terrarium drying out?
Usually because it has not been watered for a long time, or the lid has been left off. Add a little water, close the lid and check it again after a few days.
How long does a bonsai terrarium last?
With the right light and occasional care, a bonsai terrarium can thrive for years. Trim the tree as it grows so it stays in proportion with the jar.
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