Terrariums have (rightly) become a very popular way of growing houseplants. Terrariums are a great way to grow certain plants because of how well they retain moisture. They’re also a great way to see all aspects of your plants’ health at all times. Often, as the roots of your terrarium plants sprawl outwards, they become visible to us as they press against the glass. However, when creating your very own terrarium, there are many things you want to take into consideration: what plants to choose, how to stop fungus from growing inside the terrarium and how to take care of the plants in the terrarium in the long term. In this post, I’ll take you through assembly and care in 5 simple steps.
1. Choose a glass container
The first step is to choose the glass container that will house your terrarium. Opt for containers with larger openings that your hand will fit into. This will make it easier for you to insert plants and small decorations. That being said, if you don’t have a jar or container with a large enough opening, you can always use a pair of long tweezers to help you arrange the inside of the terrarium. Also think about how large your plants will get and how many you want in one terrarium. In fact, my syngonium was originally a small plant in a closed terrarium, and as it got taller, I had to make it an open terrarium by taking off the lid of the jar so it would have space to grow, and over time I had to replant it into a large glass vase, where it’s been ever since. Basically, don’t make the same mistake I did; plant your plants into a larger container if they’ll need the space in the future. In fact, for terrarium plants that don’t stay compact, some use fish tanks and custom-made terrarium receptacles.
2. Choose your terrarium plants
In general, plants with thin, tender foliage that isn’t glossy like (or at least withstand) humidity. Here’s a list of plants that do well in closed terrariums:
- Scindapsus pictus
- English ivy
- Miniature orchids
Open terrarium plants:
- Lucky bamboo
- Spider plants
Note that succulents in terrariums have slightly different requirements to other terrarium plants.
3. Add your medium
You substrate layers should include, from bottom to top: gravel/stones, charcoal, water retention and soil.
The gravel or stone layer should be about 5 centimetres (2 inches) in height. It allows water to sit at the bottom of the pot without saturating the soil. This keeps the roots healthy and stops them from sitting directly in water.
The charcoal layer is made up of horticultural charcoal, which stops fungi from growing in the very moist pot. This is also known as the purification layer. This layer should be little more than just a sprinkling will do. I’d say about half a centimetre ( just under a quarter of an inch) is more than enough.
The water retention layer is just a then layer of water retentive material that will keep the soil moist without having the soil and roots sit in water. A layer or two of clay beads or sphagnum moss will do. That being said, there are some sustainability issues with sphagnum moss, and if you’re going to use it, please try to use sustainably sourced moss, like Brunning’s sphagnum moss. Do not add a water retention layer to your terrarium if you will be planting succulents in it.
Finally, the soil layer is simply potting soil. Use enough to cover the roots of your plant. Make sure to cover the roots but not the leaves and stems, which can rot if submerged.
Note that a lot of the images you’ll see on the internet of terrariums that are taken for their aesthetic appeal will not actually have all of these layers, since those arrangements only need to last for a single picture, and having so many different layers of substrate taking up space in the shot isn’t always the most visually appealing in a photo.
4. Add your plants and decorations
This is the fun part! Play around with where you want to put things. Try to vary the height of the elements in the terrarium by adding tall, leafy plants, smaller decorations and some moss creeping along the soil.
5. Watering and care
Place your terrarium in bright, indirect light and water it when the soil looks dry. The great thing about terrariums is that you can tell when the soil is dry all the way through because it’s pressed up against the glass. Closed terrariums should require very little watering and misting, since the water that evaporates is trapped in the terrarium as water particles in the air, and when it hits the top of the closed terrarium, it’ll fall back onto the soil, kind of like rain.
If you want to get ~fancy~ with your terrarium, I would recommend checking out SerpaDesign on YouTube. His terrariums and vivariums are absolutely amazing to look at.