How To Build A Terrarium

Created By Frays and Knots

A terrarium is a miniature garden confined inside a container, usually made of glass, that is usually sealed to create its own ecosystem that is self-sustaining.

Closed terrariums created the perfect environment for having a successful ecosystem. This is because the sealed container combined with the heat and the light entering the terrarium allows for the creation of a small scale water cycle. This water vapour the condensation on the walls of the container which eventually falls back to the plants and soil below. This then contributes to creating an ideal environment for growing plants due to the constant supply of water, preventing the plants from drying out. In addition to this, the light that passes through the terrarium allows the plants to photosynthesize, a vey important aspect of plant growth.

What is a Terrarium?

You can get as creative as you want when choosing your container. Op shops, Kmart & Big W are the main suppliers that I use to find my funky glassware. You need your container to have a mouth wide enough for your hand to fit (6cm approx.) and deep enough for you to create all your layers and allow for growth in your terrarium (10cm approx. high).

If you’re looking at a super easy, low maintenance terrarium then you will need a piece of glassware with a lid. This is how the terrarium creates its own ecosystem which means less watering for you. wooden lids as these can go mouldy & spread around your terrarium. Open terrariums are just as great, (also perfect for succulent terrariums), however you will need to water more often as the terrarium cannot water itself due to no lid.

The glassware I am using in this tutorial is a 3.8L cookie jar from Kmart. Super simple glassware yet super effective. Any piece of glassware that comes with a suction ring (like the one I am using), always remove it. This will allow air to travel in & out of your terrarium instead of it pretty much suffocating if it did have a suction ring.

Choosing Your Glassware

Before We Get Started

Before we get into creating, there are just a few steps we need to do. Firstly, rinsing out the glassware. This is get rid of remaining dust particle and will make you glassware more clear. Use paper towel to dry it.

Next is to soak you sphagnum moss. In a bowl or bucket, place all the sphagnum moss in and add room temperature water, enough to cover all the moss. Allow at least 5 minutes for the moss to soak up the water. This step can be done a few hours before making or even overnight.

Let’s Get Making!

Add Drainage Layer

Let’s add your first layer, pebbles. You want an even layer of pebbles, about 1cm in width, you can use the width of your finger to measure. The best size of pebbles to use in a terrarium are 3mm - 8mm. We are using 6mm pebbles now.

Depending on how large your glassware is, you may have leftover pebbles; these can be used for decorating the top so set them aside to use later.

Once the moss has soaked up the water, squeeze any access water out of it & pull the moss apart. Place on top of you first layer (pebbles). Firmly press the moss into the pebbles. This layer is going to create a barrier between the pebbles & soil. The firmer you press, the more even the layer will be.

Using the width of your finger again measure the moss to create an even layer. This will then create your second layer of the terrarium.

Add Moisture

Add the charcoal on top of the sphagnum moss. I prefer to have the charcoal in the centre of the terrarium, avoiding touching the glass ware. The charcoal is still 100% functional, I prefer to hide it as the charcoal can be quite chunky sometimes.

Next up is adding the soil. This layer needs to be at least 4cm deep to ensure the plant roots are submerged. Firmly press down the soil. This will ensure that once your plants have been added & watering the soil doesn’t sink. The best type of soil to use is any premium potting mix or bonsai mix.

Add Charcoal then Potting Mix

Gently squeeze the sides of the pots that the plants are in to loosen the soil. Pull the plants from the pot, make sure that the roots are still in tack or otherwise the plant won’t take & won’t live. Using your finger, create a hole big enough & deep enough for the roots of the plants to sit comfortably in. Place the plant in the soil & use the surrounding soil to lock it into place. Be sure that all the roots are underneath the soil. If your terrarium has a lid, make sure that you have created a hole deep enough so that the plant isn’t touching the lid. Repeat this as much as you need to make sure that you’ve found the perfect spot for your plants. Using a water spray gun, give your terrarium a spray. Dry the inside of the glass with paper towel before decorating

Let’s Add Some Greenery!

Woohoo the best part! Decorating! In your kit there’s natural rocks & sand for you to add. Go wild! Let your mind run free! You can add beautiful things from nature like, live moss, sticks, driftwood & pebbles. Give you terrarium a sparkle & add crystals! You can get as creative as you want! You don't have to completely cover the top either. If you do decide to use driftwood or sticks that you have found, be sure to sanitise them beforehand to avoid nasty, unwanted bacteria that can lead to fungal diseases & to eliminate the risk of pests. I prefer to cover the whole top with sand then add rocks on top. If adding moss in an open terrarium, the moss will need to be watered at least once a day. Moss requirers constant moisture & the moment it drys out, it is unlikely to come back to life.

Once your beautiful terrarium is complete, give your terrarium a spray. Be sure to really give it a good, even water. Because you added dry soil it will need a big water to ensure the water can reach the sphagnum moss & essentially ‘active’ your terrarium. I usually use a whole spray bottle to ensure that the terrarium has had an even watering but without drowning it. Wipe down the inside & outside of your terrarium with paper towel. If you have a closed terrarium pop your lid on. Find a new home for your terrarium with plenty of bright, indirect sunlight.

Be sure not to over water your terrarium, although it has drainage layers they don't drain as quick as you think!

How To Look After Your Terrarium

Click below to find important tips on how to care for your terrarium