IN THE pursuit of both an interesting interior and the need to bring plants indoors, we did some research. Indoor plants have always been a celebrated part of interior design, whether in the home or in an office. We found out about Terrariums in the process and thought we should share, whilst going through the process. Terrariums are usually sealable glass containers containing soil and plants, and can be opened for maintenance to access the plants inside. However, terrariums can also be open to the atmosphere rather than being sealed.

Terrariums are often kept as decorative or ornamental items. Closed terrariums create a unique environment for plant growth, as the transparent walls allow for both heat and light to enter the terrarium. The sealed container combined with the heat entering the terrarium allows for the creation of a small scale water cycle. This happens because moisture from both the soil and plants evaporates in the elevated temperatures inside the terrarium. This water vapour then condenses on the walls of the container, and eventually falls back to the plants and soil below.

This contributes to creating an ideal environment for growing plants due to the constant supply of water, thereby preventing the plants from becoming over dry. In addition to this, the light that passes through the transparent material of the terrarium allows for the plants within to photosynthesize, an important aspect of plant growth.

According to Wikipedia, the first terrarium was developed by botanist Nathaniel Bagshaw Ward in 1842. Ward had an interest in observing insect behaviour and accidentally left one of the jars unattended. A fern spore in the jar grew, germinated into a plant, and the terrarium was born. The trend quickly spread in the Victorian Era amongst the English. Instead of the terrarium, it was known as the Wardian Case. The story goes that Ward hired carpenters to build his Wardian Cases to export native British plants to Sydney, Australia. After months of travel, the plants arrived well and thriving. Likewise, plants from Australia were sent to London using the same method and Ward received his Australian plants in perfect condition. His experiment indicated that plants can be sealed in glass without ventilation and continue thriving.

Closed terrariums also require a special soil mix to ensure both good growing conditions and to reduce the risks of microbial damage. A common medium used is ‘peat-lite’, a mixture of peat moss, vermiculite, and perlite. The mixture must be sterile in order to avoid introducing potentially harmful microbes. Because of the different conditions within, terrariums can be classified into two types: closed and open.

CLOSED TERRARIUMS

Tropical plant varieties, such as mosses, orchids, ferns, and air plants, are generally kept within closed terrariums due to the conditions being similar to the humid and sheltered environment of the tropics. Keeping the terrarium sealed allows for the circulation of water, but terrariums must be opened once a week to remove excess moisture from the air and walls of the container. This is done to prevent growth of mould which could damage the plants and discolour the sides of the terrarium. Terrariums must also be watered occasionally, the absence of condensation on the walls of the terrarium or any wilting of the plants is an indicator that the terrarium requires water.

OPEN TERRARIUMS

Open terrariums are better suited to dry plants such as succulents. Not all plants require or are suited to the moist environment of closed terrariums. For plants adapted to dry climates, open, unsealed terrariums are used to keep the air in the terrarium free from excess moisture. Open terrariums also work well for plants that require more direct sunlight, as closed terrariums can trap too much heat potentially killing any plants inside. Some further categorize them into Airplants, Cacti, Moss, Succulents and Tropicals (although this covers some of the other kinds to an extent). Now that we know what they are, we sourced commonly asked questions from ambius.com, a site dedicated to plant knowledge: What supplies do you need to make a terrarium? You’ll need the following:

• A glass or plastic container
• Rocks, if you choose
• Moss, if you choose
• Soil (growing medium)
• Plants that won’t overgrow (generally miniature or dwarf plants)
• Spoon for placing soil
• Long tweezers for putting materials into vessel

HOW DO YOU MAKE TERRARIUMS?

1. Buy a special terrarium case to hold your garden or make one of your own out of a soda bottle, fish tank, fish bowl or vase.
2. Then fill the bottom of your container with half the amount of the layer of soil you plan to use. You may lay rocks as your first layer in the terrarium, but this up to personal preference.
3. Add any large rocks or pieces of driftwood that you would like to include in your garden.
4. In the soil, make a hole big enough for the roots of the plants to rest.
5. Remove the plant from its container – you may need to lightly massage the roots to loosen the roots from the soil.
6. Position the plants in the thin layer of soil and add the second layer of soil around the plants. Press somewhat firmly – the new soil level should be about the same level as the soil of the plant’s original root ball.
7. Get creative and mix up the plants, colors and sizes.

WHAT PLANTS WORK BEST IN TERRARIUMS?

Typically, foliage plants and plants that grow slowly work best – avoid fast growing plants. For example:

• Ferns – Maidenhair, Birds nest, Button ferns
• Carnivorous plants – Venus fly traps, Pitcher and Sundew plants
• Dwarf palms
• Airplants – Tillandsia
• Succulents- cacti, Hawthornia, Echeveria, Crassula, etc.
• Peperomia Ferns, carnivorous plants and airplants are quite difficult to grow without terrariums. So, if you would like these plants in your home, we recommend purchasing or making a terrarium.

WHAT ARE THE BENEFITS OF TERRARIUMS?

There are quite a few benefits of terrariums, such as:

• They help grow plants that would be difficult to grow in dry air.
• They provide a confined space for a garden – a ‘mini garden.’
• You can use artificial light, such as LED or fluorescent very efficiently.
• Terrariums don’t need to be watered often. How do you care for terrariums? Terrariums are low maintenance for the most part but we do have some suggestions to keep your terrarium long lasting and healthy.
• If you choose to grow ferns, trim leaves to prevent them from overgrowing.
• Make sure to remove yellow and brown leaves from any plants in your terrarium. This is typically a sign of disease or pest.
• If you have an open terrarium, monitor for pests such as gnats or mealy bugs.
• If you have closed terrarium, you may want to remove the lid every now and then to let in some fresh air.

What happens if my terrarium gets bugs?

We recommend buying insecticidal soap from your local gardening store and applying it to infected plants. You can also buy pebbles or rocks to deter gnats and avoid over-watering. But, if all else fails and the plant is still infested, it’s best to remove the entire plant. Plants for terrariums are typically inexpensive and keeping a sick plant in a terrarium could easily harm other plants close by. While buying plants for your terrarium, check for bugs prior to purchasing to save yourself time and money.

Do you have to water terrariums?

Yes, but not as frequently as typical indoor plants. The types of plants found in terrariums tend to be hardy plants that don’t require frequent watering. Also, the greenhouse-like structure of terrariums recycles water instead of evaporating water into the ambient air with normal indoor plants.

How often do you have to water terrariums?

If closed, you might be watering them (on average) once a month but this will vary depending on a variety of factors. Open terrariums benefit from being watered every 3-6 weeks. Rather than watering on a schedule, check the soil to see if and how much water your plants need.

Do terrariums need sunlight?

Most need either direct or indirect light but artificial light may also be used. There are three types of light you can provide for your terrarium.

• Direct sunlight
• Indirect sunlight
• Artificial light

It is recommended to use fluorescent or LED bulbs. Avoid incandescent bulbs.

If you choose to place your terrarium in direct sunlight, you may want to remove the lid on a closed terrarium because it might get too hot for the plants with the lid on.

Do terrariums need to be airtight?

Terrariums are fine if they are airtight, but we suggest removing the lid periodically (about once a week or even daily) to allow fresh air into your garden.

Can terrariums be made of plastic?

Sure! Plastic containers, like those made out of acrylic, work just fine. You can also buy antifog plastic containers, which prevent condensation build-up and allows better visibility – these are generally more expensive.

How long do terrariums last?

Terrariums can last anywhere from several years or even longer, if well maintained.

Do terrariums need air?

Yes, but plants in airtight, or closed terrariums, recycle air. During the day, sunlight promotes the growth of sugars during the process of photosynthesis. Photosynthesis converts carbon dioxide into oxygen, releasing it into the terrarium. In a closed terrarium, you may want to remove the lid to let fresh air into the terrarium, but a closed terrarium will not damage the plants.

Which kind of containers work best for terrariums?

Glass candy jars, fish tanks with light bulbs, goldfish bowls and coffee pots all work very well as terrarium containers. You might even choose to use a wine bottle, but planting would be difficult due to the narrow opening.

Can you plant trees in terrariums?

Bonsai trees or small junipers might work but that’s about it. What are hanging terrariums? They are simply terrariums that hang from a structure, like a wall sconce.

What is the difference between indoor plants and terrariums?

Indoor plants (houseplants) are typically used in terrariums. However, most plants chosen for terrariums are slow-growing and many are plants that are otherwise difficult to grow without high humidity or high light.

What type of soil works best in terrariums?

Coco – coir, peat moss or houseplant soil works with most plants, besides succulents which prefer a well-drained inorganic medium. Some people choose to make their own soil but if you’re short on time, garden store houseplant soil works just fine. For succulents, you’ll need soil with a sand or gravel mixture.

Do terrariums make good gifts?

Of course they do! Not only are they low maintenance, but they’re a beautiful addition to any home, apartment or business.

Do terrariums smell?

In general, no. They actually smell quite nice with an “earthy” odor. But, if yours happens to smell rotten, it’s most likely a sign of root rotting or overwatering.