How to make a terrarium

Want to learn how to make a terrarium? Terrariums are a lovely means of creating small gardens inside the house, and are often used to grow succulents and ferns. Planting flowering plants in an open-topped glass jar creates a pretty indoor garden that will bring colour and beauty into your home. Find out how to make a simple open terrarium in this guide – and find online suppliers for all the kit, below, too.

Get more garden ideas for plants and more at our dedicated page.

Psst... Struggling to get your hands on plants? Well they are key to making a terrarium, so we have also rounded up all the stores that you can order plants online from at the bottom of this feature. 

• DIY alternative planter ideas – they're very pretty!
• Small garden ideas – bright ideas for tiny spaces

You will need:

• A large glass jar
• Gravel
• Ground charcoal (or terrarium soil)
• Potting compost 
• Scoop
• Helleborus niger (choose an alpine variety with a small root ball)
• Viola x wittrockiana (pansy)
• Humata tyermanii (bunny fern)
• Moss
• Soft paintbrush

Step one: layer the bottom of the jar 

Clean and dry the jar thoroughly before you start. Carefully place a layer of gravel in the bottom of the jar (adding it in handfuls rather than pouring it in, so that it does not shatter the glass). The gravel should be about 2cm thick and evenly spread over the bottom of the jar.

Step two: add the charcoal powder

Sprinkle charcoal powder over the gravel, completely covering it. This will help to absorb odours from the potting compost, ensuring that the terrarium does not smell.

Step three: Add the potting compost 

Check that the potting compost is damp before using—water it if necessary, letting it drain slightly before using it. Add the potting compost to the jar, making a layer about 5cm thick. Add it using a small scoop or your hand rather than pouring it in, so that it does not make too much mess inside the jar.

Step four: start planting out the terrarium

Take the hellebore (or alternative) out of its pot and carefully remove any excess soil from around the roots. Make a shallow dip in the potting compost inside the jar and place the hellebore in it, spreading the roots out a little and anchoring it in place with a little more potting compost if necessary, so that it sits firmly upright.

Take the pansy from its pot and plant in the jar in the same way, placing it toward the back of the jar, next to the hellebore.

Add the fern, again removing excess soil from the roots, and plant toward the front of the jar, adding more potting compost if necessary. Firm around all three plants so that they sit firmly in the compost.

Step five: add the moss

Tear the sheet of moss into pieces and place them on the surface of the potting compost, around the plants. Make sure that all the potting compost is covered, adding smaller pieces of moss if necessary.

Step six: clean up 

Using the soft paintbrush, clean up the inside of the jar and brush any bits of potting compost from the leaves and flowers to tidy them up.

How to care for your terrarium 

Make sure that the potting compost remains moist but not too wet (stick your finger into the compost to check), watering sparely when necessary. Keep the terrarium indoors in a light spot and deadhead the pansy regularly. With the right conditions, the plants should keep flowering for several weeks or even months, but the foliage will look lovely too.

DIY terrarium kits

If buying all the various elements of this beautiful project seems too much like hard work, you can buy DIY terrarium kits from online retailers such as Amazon. Click the link to go straight to their dedicated page.

Where to buy plants online right now

Read more gardening DIYs: 

• How to make pallet furniture
• How to build a birdhouse
• Vertical planters: how to DIY a living wall planter