Terrariums are currently very fashionable in garden centers and florists. These glass containers, with or without a transparent lid, are generally decorated with mixed plantations of small plants, creating a miniature garden effect; they are both decorative objects and miniature ecosystems. Originals and full of charm, they highlight the plants they shelter. However, the specific growing conditions (humidity, limited space, rare substrate) imply some precautions.
Most people buy a terrarium to get a taste of indoor gardening adding a beautiful décor to the home.
Terrarium meaning / What is a Terrarium
The terrarium is a miniature ecosystem, most often confined in a glass jar, and in which plant species such as tropical plants or succulents can grow. The water in the aquarium is replaced in the terrarium by another natural element such as soil or sand. When you want to buy a terrarium, you’ll distinguish different categories of terrarium: Closed terrariums and open terrariums.
Indeed, the choice of plants and the maintenance of the terrarium is made according to the desired mini-ecosystem; it takes into consideration certain elements such as light, temperature, watering, as well as the size of the plant species.
With little equipment and some instructions we’re going to give you, setting up one of these terrariums at home will be relatively easy.
Setting up a Terrarium
Choosing the right Terrarium Container
The first step to set up your terrarium is to choose the best container. It must be made from rigid material (glass, plexiglass, plastic…), waterproof and allowing light to pass through perfectly. You can use an old aquarium, a vase, a coffee pot, a jar …
Depending on the type of plants you will be installing inside your miniature garden, the shape of the container is important. It’s also important that the opening will be wide enough to allow handling (plantation and caring for terrarium plants).
The ventilation must be adapted to the terrarium plants: if you want to reproduce a desert environment (cacti, succulents), plan a wide opening terrarium container so that the atmosphere is constantly dry inside. On the opposite, plants from wetlands (tropical plants or swamps) will need high humidity, and therefore a container with a very narrow opening (beware of the risk of rot in case of lack of oxygen).
How to Make a Terrarium?
Making a terrarium is not so difficult, but unless you choose plants with very low water requirements, it is imperative to provide a drainage system for the terrarium. In fact, the bottom of the container not being pierced, the water cannot flow and its stagnation can cause rotting and bad smells.
Here are steps to build a successful terrarium:
Clean the terrarium container: If you are using a used container, you should start by washing it well with soapy water and rinse thoroughly to remove any soap residue. A dirty terrarium will develop bacteria over time, so use an antibacterial soap if possible.
Add rocks for drainage: Mix the pebbles or gravel with a generous handful of charcoal (charcoal prevents the soil from developing a sour smell) and place a 2 cm layer of this mixture inside the container.
Spread peat moss: Soak a dry moss in a bowl of water for a minute, squeeze the excessed liquid then place the moss over the charcoal layer. This will prevent the soil from seeping down into the gravel and will be a good way to remove the excess of water.
Insert the potting soil: Depending on the size of the terrarium and the length of the plant roots, you will need to add about 5 and 10 centimeters of potting soil. Gently tap it to remove air pockets and smooth the surface. Dig small holes in the potting soil where you will put the plants.
Plantation: Remove a plant from its container and strip the roots to remove the excess of potting soil and help the plant growing its roots into the terrarium soil. Snuggle it into the hole you dug previously and surround it with potting soil by tapping gently. Do the same with the other plants you plan to add.
Terrarium decoration: You can add moss or decorative stones to the top of the terrarium to design the landscape you desire.
Terrarium plants watering: Lightly water your plants to prevent transplant chock keeping in mind that overwatering can cause the plant rotting or suffocating since there is no drainage hole.
Choosing Terrarium Plants
Plants suitable for growing in terrariums and other miniature gardens must meet very specific criteria in order to adapt to the specific conditions of the environment:
- Small plants to fit harmoniously into the terrarium container;
- Slow-growing plants to keep as long as possible the appearance of the original landscape and prevent plants from crashing on the walls of the terrarium;
- Terrarium plants must all have the same cultural needs as they will be grown in the same container;
- They must have a restricted root system because the containers are rarely very deep and the potting soil layer is not very thick.
Closed Terrarium Plants
Closed terrariums, keeping a high humidity rate, they must contain plants adapted to this particular environment. Here is a list of plants that should thrive in closed terrariums:
Mosses are usually the best starting point for building a terrarium. They thrive in humid conditions with low light and they are the best choice as ground-level plants.
Leucobryum glaucum, otherwise known as “Pincushion moss ” is appreciated for its texture and its beautiful bright green color which makes it possible to form beautiful carpets as a ground for decoration; For the same job, think also of Riccia fluitans (Floating Crystalwort).
If you want a slightly more erect effect, choose Vesicularia reticulate (Erect Moss).
To “dress” a stone or a root, you can choose Marchantiophyta sp, a flashy green moss that clings very well and hugs all the contours of the support perfectly.
Ferns are flowerless, vascular plants that mainly reproduce by the production of spores. They are would do well in closed terrariums because they like the excess of moisture and humidity.
Humata tyermanii, better known under the name of Davallia, has a beautiful clear green color, a slightly creeping habit and looks stunning in terrariums.
The genus Asplenium is also well represented in these types of plants: Asplenium nidus (Bird’s-nest fern) with bright green foliage, Asplenium scolopendrium (Mother spleenwort) delicately wavy, or Asplenium bulbiferum (Rabbit’s foot ferns) very aerial and original.
Selaginella martensii (spikemoss) looks like a small, dense, green bush.
Starfish Flower Cactus
Baby Tears Plant
Miniature phalaenopsis orchid
Open Terrarium Plants
Unlike a closed terrarium, an open or dry terrarium is left open at one side at least; the larger the opening of the container, the lower is the humidity. So you can consider plants from dry or even desert environments that need more oxygen and less humidity; so many species and varieties of succulents and cacti are suitable to grow in open terrariums.
The genus Haworthia presents many species of succulents with small blooming that are ideal to plant in dry terrariums! The small foliage, still very ornamental, sometimes glaucous green dotted with white lines in Haworthia fasciata or Haworthia attenuata, forming a checkerboard on the original H. tessallata, or translucent green on H. arachnoidea or H. mirabilis.
Pebble plants (Lithops) or living stones are also ideal subjects thanks to their low development and the variety of their colors, without forgetting their originality.
If your terrarium is open on one side, you may consider using drooping plants that will elegantly overflow. Among them, Senecio rowleyanus which looks like necklaces of peas, Ceropegia woodii (The String Of Hearts) or Sedum morganianum with blue-green stems.
As for cacti, think of small easy-to-grow balls such as Echinopsis, Mammillaria, or the lesser-known Gymnocalycium. If the terrarium receives a few hours of sun daily, you will have the chance to see them bloom!
In the background, for their graphic side and their verticality, think of the small species of Prickly Pear (Barbary fig), and the small Cactus Candles which you will find many varieties in garden centers.
Terrarium Care and Maintenance
Closed Terrarium Care
It has great importance in the development of the plant. In summer, your terrarium should be placed in a space where there is a lot of light without exposing it to UV from the sun. During winter, it should be placed about one meter from a window. From time to time, you have to turn the terrarium so that all plant species can take advantage of the light.
A closed terrarium often contains tropical plants that love warmth. Ideally, have your ecosystem in a room with an ambient temperature between 15 and 27 degrees. In fact, a terrarium is often made up of plants that are used to thrive in humid and warm environments, and it is important to try to reproduce this natural climate. Sometimes a fog appears on the wall of the terrarium container; this is the result of a temperature difference between the ambient environment and the inside of the container. You just have to open it to achieve the balance so that the fog disappears. This condensation phenomenon is normal and shows that the environment lives.
Watering Closed Terrarium
The frequency of watering a closed terrarium is only 3 to 4 times a year. When the soil in the terrarium is dry, it’s time to water. For this type of terrarium, it is preferable to favor rainwater or mineral water. Tap water could be harmful due to the presence of lime.
Maintaining a Closed Terrarium
Remove the dry leaves from the jar. When it grows too fast, it needs to be pruned. However, the jar must be closed 48 hours later to allow the plant to heal. If this provision is not respected, it can die in the jar.
Terrariums need less soil to better control the size of the plant. This environment promotes small-scale development.
Open Terrarium Care
Sunlight remains an essential factor for the survival of the plant species because it promotes photosynthesis in the plant. The plant will thus be able to produce the elements necessary for its survival such as CO or even oxygen.
Your terrarium must be exposed to daylight and in the most homogeneous way possible. To do this, just remember to turn the glass jar once a month so that the plants all have access to light. During the winter season, place the terrarium as close as possible to a window, but do not place it outside. The terrarium should also not be too far from the window to avoid the risk that its light supplies are insufficient.
An open terrarium should be placed in a room at room temperature and away from too large sources of heat.
Watering an Open Terrarium
Once your ecosystem is created, you can water it once a week in winter and 2 to 3 times a week in summer. Remember to observe the moss. If the latter is dark green, then it means that your terrarium has enough water. If, on the contrary, the color of the moss becomes very light (see whitish), it is time to water it. Ditto for the substrate present in the bottom of the jar, if it is too dry, the ecosystem is lacking in water.
When you water the terrarium, take care not to put too much water. It is especially important that the water does not stagnate at the bottom of the jar at the risk of killing your terrarium.
Maintaining an Open Terrarium
Terrarium plants can grow bigger than the container. It’s important to cut them so they take less height.
Dead leaves can be removed to clean up the environment.
You now know everything about terrariums. All you have to do is buy a ready-made product or create your own.