How to Create a Terrarium – An ecosystem of its own

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How to Create a Terrarium – An ecosystem of its own

Terrariums are a fantastic low-maintenance option for maximum impact. Bottle gardens allow you to grow some truly exotic plants thanks to their high humidity. Join us as we run through the essentials to create your own miniature ecosystem.

What do I need?

You can create a terrarium with just a few simple ingredients. Primarily a glass container, this can range from old jam jars to larger containers. You can opt for either a closed or open terrarium. Open kinds are much more suited for cacti and succulents whilst closed provide a nice humid environment for moisture loving plants.

You’ll also need some gravel, stones or small pebbles to help drainage. This will be your base layer. Now obviously, you’ll need some soil – but what kind? Potting soil will work best, though most general purpose ones you can find in your Local British Garden Centre will work too. For an open terrarium, cactus specific compost is a better choice.

Optionally for a closed terrarium, charcoal can help absorb any sitting water and reduce nasty bacteria build up. Although not necessary, it will help.

Open Terrarium

What to plant

Depending on whether your terrarium is closed or open, the best choices can vary. Here we will cover the most popular choices for both.

Cacti – Cacti are your best choices for open terrariums, as a slow growing variety will need practically no attention. It’s best to mix cacti with cacti, opting for different shapes and sizes with a sandy base. You can mix cacti with succulents for a detailed display.

Succulents – Echeveria is one of the most common succulents you can find. They come in all sorts of colours and their fleshy leaves are perfect for an open terrarium. An eye-catching variety you can find is the “Mexican Snowball”. These have pale blue leaves and form in an almost rose-like pattern.

Fittonia – Also known as “nerve plant”, they are perfect for closed terrariums. They have countless varieties with different colours and patterns, from whites to reds. Fittonia love a humid environment with a lower light level. Their low maintenance growth allows them to pair well with others.

Moss -  Moss needs constant moisture to survive, and what better place than a closed terrarium. A common choice not only for its low maintenance but also as colourful ground coverage.

Asparagus Fern – An easy growing, moisture loving foliage plant. For a closed terrarium they can grow quite tall, overhanging other plants – perfect for the “miniature ecosystem” feel. Be careful handling an Asparagus Fern, as their stems have tiny thorns that can leave a nasty scratch.

Planting in a terrarium

Putting the pieces together

With your plants chosen, your materials and tools gathered, its time to fit them all together! The process varies depending on if your terrarium is open or closed.

Creating an Open Terrarium – Place a layer of grit as your base layer, this will help reduce moisture building up. Next, add your compost. Add enough relevant to the size of your cacti/succulents and gently place into the terrarium. Be wary not to prick yourself – try using some tongs or a thick gardening glove for cacti. Finally, pop in any decorations and give them a very light watering to help them settle and voilà!

Creating a Closed Terrarium Start by adding your base layer of gravel and grit and if you have some, a thin layer of crushed charcoal. Next add your layer of moist compost, enough to comfortably house the roots of your chosen plants – ideally 2-3 inches.

If your chosen jar has a small opening, getting the plants in can be quite a finicky process. A long stick with a large head or some garden tweezers can help you manoeuvre and reposition your plants around once inside. Use a stick of sorts to create a small hole for your plants to nestle into. Once you finally get them in place, flatten the compost down and add any decorations or moss.


Putting the pieces together

Caring for a Terrarium

Now you’ve created your terrarium, its time to look at the aftercare. Surprisingly, there’s hardly any!

Closed terrariums create their own ecosystem and will practically water themselves. Try to avoid opening the jar for the sake of it as this can disrupt their environment. However, if you notice plants beginning to wilt be ready to intervene. Place these away from windowsills to avoid direct sunlight.

Open terrariums will love to be planted on windowsills or in full sun positions. Cacti and succulents will need a light watering depending on the time of year. In the winter months you can get away with a teaspoon of water every two months! Although in hotter periods be sure to top them up every other week.

Pruning – Eventually your plants will grow quite out of control and will need a good cut back. Long scissors and tweezers are perfect to cut and remove excess leaves.

Sick care – If your closed terrarium is moist but the plants are browning, potentially they’re receiving too much direct sunlight. Moss is great here, because if your moss if fading it shows a lack of moisture – so give them a quick top up.

If your still unsure on caring for any houseplants, check out our Guide to maintaining indoor plants.

Closed Terrarium on shelf

Thanks for reading.

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