Christmas terrarium: build it step by step, from moss to figurines

A Christmas terrarium is an ordinary moss terrarium, dressed for winter with a few figurines. The moss stays all year. The festive decoration goes in in December and comes out in January, with tweezers. Here is how to build one in six steps, with our Moss & Light kit and our winter figurines.

How it works

A closed terrarium recycles its water. The water evaporates, condenses on the glass and runs back down. Living moss stays green with a little light and almost no watering.

The figurines change nothing in this cycle. They sit on the moss, like a table decoration. This is what makes a Christmas terrarium simple: you plant nothing seasonal, and nothing dies after the holidays.

Start from a terrarium set up a few weeks before Christmas. The condensation has time to settle before you add the decoration.

What you need

• A closed bottle and living moss. Our Moss & Light kit includes a recycled glass bottle 17 cm in diameter and 25 cm tall, 8 moss cushions, the substrate layers and an LED cork lid. The supplier does not specify the batteries for the lid.
• A set of winter figurines, 1 to 3 cm tall. The neck of the bottle is 10 cm: they go through easily.
• Long tweezers, to place the pieces at the bottom.
• Decoration for the outside: pine cones, ribbon.

The six steps

Step 1: build the moss terrarium

Allow half an hour. Add the layers in order: clay balls, activated charcoal, potting soil. Then lay the moss cushions, pressed tightly against each other. Mist, then close.

Leave the bottle in its place for a few days. If water streams down the glass all the time, open it for a few hours a day, until the condensation is light again. If the glass no longer fogs up at all, mist a little soft water.

Step 2: choose a theme

A single theme makes a clearer scene than a mix. Three ideas:

• Santa's reindeer: four reindeer about 2 cm tall, a Santa and a fir tree about 3 cm tall, and four snowflakes.
• The Christmas house: a Santa, a fir tree, two snowmen and a house, 2 to 3 cm tall, with four snowflakes.
• The snowy landscape: six snowmen, all different, 2 to 3 cm tall, and four snowflakes.

For a large bottle, our set of eight Christmas friends, 2 to 5 cm tall, adds taller pieces.

Step 3: charge the snowflakes

In these three sets, only the snowflakes glow in the dark. The other figurines do not glow.

The manufacturer recommends placing the snowflakes in full light for several hours, a whole day if possible. They then glow softly in complete darkness.

Charge them before you place them, on a windowsill or under a lamp. The terrarium itself must not go in the sun. The RHS and university guides keep it away from direct sun, which heats the glass. Our guide to the glow-in-the-dark terrarium explains the effect in detail.

Step 4: place the decoration in the bottle

1. Open the bottle and lay the lid flat next to it.
2. Place the tallest piece first, such as the fir tree or the house, a third of the way across.
3. Add the characters around it, facing the center.
4. Scatter the snowflakes over the moss, at different heights.
5. Keep a little space between the figurines and the glass.

Pick up each piece with the tweezers. Push it a little into the moss so it stands upright. Clean the figurines before you place them: university guides recommend this for any object added to a terrarium.

Step 5: dress the outside

The outside decoration does not affect the balance inside the bottle. This is where natural materials go.

• Pine cones at the foot of the bottle. Our product page lists them for an open terrarium or an arrangement. The supplier does not say if they are treated: inspect them before you place them near living plants.
• A ribbon tied around the neck. Penn State Extension mentions holiday ribbon as a seasonal decoration that barely disturbs the terrarium.
• Preserved reindeer moss, as a cushion around the base. It is not alive and needs no watering.

Reindeer moss can also go inside the bottle, as surface decoration. It does not replace living moss. Our guide living or preserved moss explains the difference.

Step 6: choose the spot

In December, the terrarium often moves for the festivities. Keep three rules:

• Indirect light, never direct sun on the glass.
• Away from heating. The RHS recommends keeping terrariums away from heat sources.
• Away from candles. Health Canada says never to burn a candle near flammable decorations, and never to leave one unattended. The LED lid lights the scene without a flame.

Our guide to the terrarium in winter covers the radiator and the cold windowsill in detail.

After the holidays

Take out the figurines with the tweezers, without touching the moss. Rinse them in clean water if needed, dry them, and store them in a closed box. Keep the box out of reach of children under 3: these are decorative objects, not toys.

The moss terrarium stays in place. In spring, you can add other figurines. Our guide to terrarium figurines gives ideas for the rest of the year.

In short

1. Build a moss terrarium a few weeks before the holidays.
2. Choose a single theme of figurines, 1 to 3 cm tall.
3. Charge the glow-in-the-dark snowflakes before you place them, never the terrarium in the sun.
4. Keep the pine cones and the ribbon outside the bottle.
5. Place the terrarium in indirect light, away from heating and candles.
6. Take out the figurines with tweezers in January and store them for next winter.

Sources

• Bottle gardens and terrariums, RHS
• Creating a Closed Terrarium, Penn State Extension
• How to Create and Care for a Terrarium, Iowa State University Extension
• Sécurité-incendie chez vous, Santé Canada (in French)
• Manufacturer data sheets (bottle dimensions, contents of the figurine sets, charging the glow-in-the-dark snowflakes, preserved moss, pine cones)