Demijohns are large, bulbous glass bottles that make for stunning closed terrarium projects. Their rounded shape provides ample space for creative planting, and their glass construction perfectly showcases the mini ecosystem within.
If you can get your hands on a demijohn bottle follow these steps to create your own unique glass bottle garden terrarium.
Supplies Needed
- Demijohn bottle – 25L or larger recommended
- Activated charcoal
- Horticultural sand or gravel
- Terrarium soil mix
- Sheet moss or dried moss
- Assorted small tropical plants
- Chopstick or long tweezers for planting
- Funnel (or rolled paper)
Step 1 – Create Drainage Layer
The first step is establishing proper drainage at the bottom of the demijohn. This is crucial to prevent soil from getting waterlogged.
Add a 1-2 inch layer of horticultural sand or gravel This will allow excess water to drain away from the soil,
Top with a thin layer of activated charcoal to help filter the water and prevent odors. Charcoal also looks nice as a separating layer.
Step 2 – Add Terrarium Soil
Next, add your terrarium soil mix. Aim for a 2-3 inch depth, though you can adjust based on your planting plans.
Use a funnel to direct soil into the narrow bottle opening. A rolled cone of paper can work too. Add a little at a time to prevent clogging.
Optional – place decorative stones or pebbles along the sides over the drainage layer. This hides the filtration layers and looks more natural.
Step 3 – Plant the Terrarium
Now comes the fun part – selecting and adding your plants! This is where tweezers or chopsticks come in handy for lowering plants into place through the tiny opening.
Tips for plants:
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Choose short, slow growing species that won’t outgrow space
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Miniatures, mosses, and succulents work well
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Opt for plants that can handle high humidity
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Mix textures, colors, and leaf shapes for visual interest
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Start with a focal point plant like a small fern or vine
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Add accent plants like selaginella,Pilea,and creeping plants
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Top with a moss layer such as mood moss or sheet moss
Take your time arranging plants and enjoy the creative process! Mist occasionally between plantings to keep soil moist.
Step 4 – Finish and Enjoy
Once planted, place your terrarium in a brightly lit spot out of direct sun. Mist lightly to help plants settle in. Over the next few weeks, monitor soil moisture and condensation.
Eventually your terrarium will reach an equilibrium, needing only occasional misting. Now you can sit back and enjoy watching your tiny glass world thrive!
Demijohn terrariums are sure to become a beautiful focal point wherever they’re displayed. Just be sure not to overwater or overplant them. With proper care, your glass bottle garden can last for many years!
What is a terrarium?
Terrariums have their origins back in Victorian times. In 1842, a botanist named Nathaniel Bagshaw Ward found them by accident when he saw fern spores growing successfully in a jar. The Victorians, who liked strange and exotic things, thought it would be great to be able to grow tropical plants in glass containers. These containers quickly became a must-have for any home.
It looks like every trend has come full circle, and terrariums are now all over major magazines. You can’t move on Instagram without seeing terrariums filled with ferns and succulents. They’re even sold at Urban Outfitters! But it’s much more fun and easier to make your own than to buy one!
But before we dive into the “how-to” it’s important to understand how they work. Terrariums are basically small gardens that are made inside of glass containers. There are two main types: those that are open and those that are closed.
Closed terrariums are the ones I find most magical. They are a self-contained eco-system in which tropical plants thrive. The plants can live for years with just a little water if they are kept in the right conditions. Keeping the terrarium closed lets the water move around while the plants do photosynthesis. As they do this, they make gas, which settles as condensation on the glass, drips down to the soil, and the process starts all over again. But sealed terrariums need to be opened every so often to get rid of extra water. If condensation stops forming on the glass, a little help might be needed with a spray of water.
Even though open terrariums are very popular on Instagram, they work best for succulents and cacti that like it dry.
- A “vessel” like a demijohn, kilner jar, carboy, or boiling flask You could use a fish bowl or a geometric terrarium if you have succulents.
- Stones – washed before using.
- You can buy activated charcoal at health food stores. Terrariums that are sealed must have this.
- Compost – part John Innes 1 and part potting compost.
- You can pick from moss, ferns, fittonias, ficus pumilas, and variegated ivy as small plants. You can also use orchids and basil. If you’re making an outdoor terrarium, you can use succulents and cacti as well.
- A funnel.
- A long, pointy stick that looks like those thin green garden canes
- A radiator paint brush.
- A stick with a cork on the end-sounds weird, but this will be VERY useful.
- Garden cutters.
- Long tweezers.
How to make a terrarium
- Start by pouring a layer of stones into the bottom of your vessel using the funnel as a guide. This should be at least an inch thick. Leave some stones out to look nice; don’t use them all.
- Sprinkle about 1 teaspoon of activated charcoal on top of the stones, and use your pointy stick to make sure it’s spread out evenly.
- Next, use the funnel to help you fill your container with compost until it’s just under half full.
- Press down on the compost with the cork on a stick until it is firm.
- Use the radiator paint brush to clean the sides of the container.
- Pick out the first plant you want to put in the back of your terrarium. To see only the roots, take it out of its pot and shake off as much of the compost as you can.
- Get rid of any leaves that are lying low on the plant; you don’t want them to touch the compost.
- Make a hole where you want to put your plant with your pointy stick.
- Move the plant slowly into the pot and put it as close to the hole as you can.
- With the pointy stick and the cork on a skewer, you can fill the hole back up with compost and move the plant until it stands up straight.
- Do this again and again until all of your plants are in place. Clean up any mess you make on the sides of the vessel with the radiator paintbrush.
- Put any stones or moss that you want to look nice around the plants using the long tweezers.
- Spray a fine mist around the edges of the container until a dark, wet ring appears on top of the compost.
- Put it somewhere warm and sunny, but not in direct sunlight, and cover it with a cork or lid.
Every other evening for the first two weeks, take off the cork or lid of a closed terrarium. This lets the vessel breath as the plants settle into place.
If the plants in a closed terrarium look like they are wilting and condensation has stopped forming on the glass, it’s time to water it.
Open terrariums should be spritzed with water roughly once a week.
I had a fantastic time at the workshop. Emma was a wonderful host and fantastic at giving support and guidance. Sometimes it was annoying when the plant wasn’t going where you wanted it to, but Emma had a lot of great tips that would help you get what you wanted.
I’m so pleased with how to terrarium turned out. What do you think? Now we just need to put it somewhere warm and sunny.
If you interested in attending a workshop then do check out the London Terrarium’s website here. You can choose the demijohn (the one I attended), boiling flask or tinyjohn workshops where everything is included or why not bring your own vessel?
Before you ask, I’ve not been paid to promote Emma’s workshops. I just had such a fantastic time I can’t help but recommend them. If you do go along let me know. I’d love to see what you create! Make sure you tag me on twitter or instagram!
Making a Bottle Terrarium + Closed Terrarium Basics
FAQ
Can you make a terrarium in a demijohn?
Which kind of containers work best for terrariums?
How do you make a terrarium in a demijohn?
If you’re looking for a fun and easy project to add some life to your home, making a terrarium in a demijohn is a great option! All you need is a clean, clear glass jar with a wide opening, some rocks or pebbles, potting soil, and a few small plants. To start, gather your supplies and choose a location for your terrarium.
Are demijohn terrariums easy to plant?
Demijohn terrariums are easier to plant… but not that much easier. Color – Sure, a lovely green or amber bottle has instant aesthetic appeal, but it’s also going to reduce the amount of light that your plants inside can receive. Not to mention somewhat blocking your view of the plants. Stick to clear bottles, and you can’t go wrong.
What is a demijohn terrarium kit?
A demijohn terrarium kit is a great way to grow your own plants and herbs. The kit includes a glass demijohn, a metal stand, and a lid. The demijohn has a wide mouth and a small neck, making it easy to fill with soil and plants. The metal stand raises the demijohn off the ground, allowing for drainage and aeration.
How do you clean a demijohn terrarium?
Thoroughly clean the demijohn glass container with warm water and dish soap. Rinse it well to remove any residue. If your demijohn container has a narrow neck, you may need to use long tweezers or chopsticks to help you arrange the plants and other elements inside. Proper drainage is essential for the health of your terrarium.