One of my favorite experiments with houseplants is creating self sustained terrariums. These projects require very little care and are so much fun to make. I’ve already made three terrariums and it’s now my favorite hobby.
Here’s everything you need to know about building terrariums and how to keep these self-sustained containers thriving.
What is a terrarium?
First of all, what is a terrarium? Terrariums are essentially mini eco systems inside a glass container. These containers usually include soil, plants, figurines, and some people even put beneficial bugs inside.
Can a terrarium be self-sustaining?
A self sustaining terrarium is an ecosystem that’s able to provide for itself without additional assistance.
For most of us, we’ll likely need to mist or water the terrarium every now and then, especially if it’s an open terrarium.
The oldest self-sustaining terrarium is over 60 years led created by David Latimer of England. He built the terrarium in 1960 and last opened it in 1972. This means the terrarium has been growing without any additional assistance (no additional air, water, fertilizer, etc.).
How is it possible for a sealed jar garden to have survived for 60 years without any material going in or out?
A lot of people wonder how it’s even possible that this self-sustained terrarium lives without assistance for over 60 years. This is possible because the container creates a small-scale water cycle. The moisture from the soil and plants evaporates, which leads to the water vapor condensing on the walls, which eventually falls back down on the plants. Yep, it’s so cool!
How long can a self-sustaining terrarium last?
A self-sustaining terrarium built properly can live without care indefinitely. However, this is quite difficult to achieve if you’re just starting out building terrariums as there are a few key things you need to get just right.
Lighting, the right kind of plants, growing container, water, humidity and even insects need to be just right in order for the terrarium to be self-sustaining.
What plants can I put in a self-sustaining terrarium?
This is the fun part – you can put a wide variety of plants in self-sustaining terrariums. This includes cacti, succulents, and even tropicals. My favorite plants to put in terrariums are Tillandsia (air plants), Echeveria, moss, ferns, begonias, calatheas, and so on. I particularly love putting calatheas and ferns in terrariums because these are high humidity plants, and terrariums are naturally high humidity.
What do you need to make a self-sustaining terrarium?
After making a few terrariums myself, I’ve realized you only need a few key items. You don’t even have to buy new plants for your terrarium, you can simply take cuttings from plants you already have around the house.
Yep, you can put insects into a closed terrarium. You probably wouldn’t want to put insects into an open terrarium because they’ll escape pretty easily.
There are tons of beneficial insects you can put into terrariums including springtails, worms, snails, spiders, and more. You may want to consider springtails because they eat mold, which is a common problem in terrariums.
Does a closed terrarium need to be airtight?
Closed terrariums don’t necessarily need to be airtight, but they can be. These containers recycle air if the terrarium is airtight. However, you’ll want to open your terrarium to get fresh air about once a week.
Photo by Karolina Grabowska: https://www.pexels.com/photo/person-holding-a-circle-corkboard-4751994/
Do you need to water closed terrariums?
Closed terrariums need some kind of water or misting. If you notice the soil is completely dry or the leaves are starting to look a little sad, this is a sign to water the terrarium. I personally prefer to thoroughly mist my terrariums rather than just dumping a bunch of water into the container.
Are terrariums hard to maintain?
Terrariums aren’t necessarily hard to maintain, but there are things that will make it easier. For example, your closed terrarium will greatly benefit from getting fresh air at least once a week. If you have an open terrarium, this doesn’t matter.
Springtails and other beneficial insects will make things go much more smoothly in your terrarium. This is because springtails eat mold, mildew, and bacteria that grow on decomposing material.
Charcoal is one of the best things you can put into a closed terrarium. This is because charcoal absorbs toxins and odors that build in your terrarium. However, this is completely optional. I decided to add charcoal to my terrariums just to make things easier on me.
Photo by Timi Keszthelyi: https://www.pexels.com/photo/plants-in-a-glass-container-4650142/
How long does a terrarium last?
Terrariums can live a very long time and even outlive you if they’re built correctly. The current longest living terrarium is over 60 years old, so it’s very possible you can do this, too.
How often should you mist your terrarium?
A closed terrarium need to be misted whenever the plants start to look a little sad or when you notice there’s no condensation on the walls. How often you mist greatly depends on how large your terrarium is, what kind of soil you’re using, and the kind of sunlight the terrarium is getting.
An open terrarium is much difference than a closed terrarium. This is because there’s a lot more air flow going into the open terrarium, allowing the soil to dry out. You’ll probably mist and water an open terrarium once a week.
What’s the difference between vivarium and terrarium?
The main difference between a vivarium and a terrarium is one thing – vivariums are designed to be a habitat for an animal.
Should I put worms in my terrarium?
Worms are living things that are beneficial for terrariums, however, most of us are creating small terrariums that aren’t big enough for worms.
How do plants get carbon dioxide in a closed terrarium?
Plants get carbon dioxide in a closed terrarium through a process that happens at night. When there’s no sunlight, respiration will occur. Oxygen is taken in by the plants which leads to carbon divide being produced.
Can a terrarium be sealed forever?
A terrarium that is perfectly made can be sealed forever. For people new to building terrariums, making everything just right is a bit tricky so you’ll likely need to open your terrarium once a week to mist the container and give it fresh air.
If you notice signs that your closed terrarium is dying (mold, plants looking sadder and sadder despite getting misted) you may be overwatering the terrarium or not giving it enough sunlight. Make sure the plant is sitting in a spot getting bright indirect sunlight.
Yes, you’ll likely want to open your terrarium once a week to give it fresh air. This is also a great time to mist your plants.
Are open or closed terrariums better?
One isn’t necessarily better than the other. They both serve different plants.
For example, you may want to put high humidity, tropical houseplants in a closed terrarium. This is because this environment is naturally high humidity.
An open terrarium will be much dryer, making it a great container for cacti and other low humidity plants.
How do you keep a terrarium from getting moldy?
Mold is a common issue with terrariums. There are a few key things you can do to prevent mold:
What are common mistakes made when building a terrarium?
The most common mistakes made when building a terrarium include:
Not using proper well-draining soil
Using plants that don’t like high humidity or closed terrariums
Direct sunlight (don’t do this!)
Too much water
What do you put in the bottom of a terrarium?
Terrariums don’t have drainage holes at the bottom of the container, so it’s important to create some kind of drainage at the bottom. I did this by creating a two inch bottom layer of chunky rocks.
There’s a science to layering terrariums. This is because you want to allow proper drainage to flow from one substrate to the next. The correct order is: drainage layer (rocks), terrarium soil layer (well-draining mix), hardscape (rocks), plants, and figurines or other decorations.
Can moss grow in closed terrariums?
Moss does great in closed terrariums, but not open terrariums. Moss needs high humidity which is why closed terrariums are ideal. Mist the most once a week to keep the humidity high in the terrarium.
Can I use potting soil in terrarium?
Yep, but make sure the potting mix you use is well-draining as the terrarium needs proper airflow through the roots. Well-draining soil also allows any excess water to flow down the soil into the bottom layer of rocks.
Can succulents go in a terrarium?
I prefer to put succulents in an open terrarium. This is because closed terrariums have very high humidity. You wouldn’t want to mix cacti and ferns together because the humidity needs are much different.
How do I know if my terrarium is overwatered?
You’ll know if your terrarium is overwatered if the plants start to rot or there’s too much condensation on the glass container. If you think you overwatered, open the container and allow air flow overnight. Check the container in the morning and if you think it needs more air flow, leave it open throughout the day.
How much light does a terrarium need?
Terrariums need about 6 hours of light throughout the day. Make sure the container is never sitting in direct sunlight as this can cause problems inside the terrarium.
Key takeaways
Terrariums are a blast to build. Once you build one, you’ll want to keep building more. Terrariums also make for thoughtful, unique gifts that really stand out.
Have you ever made a terrarium? They are a ton of fun to create and make for a great activity to make with friends and family.
