Terrarium: A garden in a jar

7 min read

Tarrium? Terranium? It’s terrarium. Sometimes misspelt and confused with an aquarium, this garden in a jar has much to offer. Terrariums create therapeutic space for your office desk – for those moments where meetings or deadlines have had you face down on your desk. With their stylish looks, they can be fantastic greenery additions to your homes and take up minimal space as compared to a garden area. To add on, you can even unleash your creativity by making one as it is extremely fun to do so. These pretty-looking terrariums are also easy to take care of. For science aficionados, terrariums provide the opportunity of viewing a unique plant ecosystem at the convenience of your homes or desktop.

Choose from beautiful open-angled jars, fishbowl terrariums or sleek hanging terrariums to fit your style. Perhaps you might think that those designs are far too flashy or expensive, then opting for a simple closed-jar terrarium would be the best. Easy on the pockets, simple, and yet a beautiful accessory addition.

You can either choose to buy a ready-made one or make one yourself. Of course, I would recommend you make one. You can purchase a DIY kit, complete with decorations, plants and all the materials needed, for less than 20 dollars. Even better, you can even upcycle those old jars or plastic bottles and give them a new breath of life by converting them into a terrarium jar. Furthermore, you are more likely to care for it more when you make one from scratch.

Worried because you do not have green fingers? No worries! As mentioned, terrariums are very easy to maintain. For closed-jar terrariums, opting for moisture and warmth-loving plants such as mosses and Fittonia are great choices to allow them to flourish naturally. The best part is you only need to open the jar once a month for a fresh change of water! For open-jar terrariums, hardy plants such as cacti, succulents or even air plants are perfect options. These low-maintenance plants will mean that you only need water them once a weekly or even less. Ideal for those who are worried about forgetting to water their plants.

What makes up a terrarium other than the plants? 3 main layers make up all the “earth” in a terrarium. The first layer (bottom layer) is usually laid with small gravel or pebbles for water drainage. When you water your terrarium, it is possible that water pools at the bottom of the jar. These pebbles allow for water to flow evenly across the bottom layer to prevent waterlogging of the soil. If the soil is too wet, this results in a lack of oxygen for the roots. Furthermore, these wet conditions can promote mould growth in the root regions, causing the roots to rot and the plants to die.

The second layer is equally important in preventing waterlogging and usually consists of dried sphagnum moss or charcoal. These substrates have high moisture-holding capabilities. Sphagnum moss can take in water as much as 20 times its dry weight! This barrier layer soaks up any excess water pooling in the bottom layer or within the soil layer. These 2 layers are vital in ensuring proper water circulation in your terrarium to ensure the healthy growth of your terrarium plants.

The last layer is soil for planting your chosen plants. As your plants are grown in a small amount of soil, picking a nutrient-rich soil will do great for keeping your plants healthy. Organic soil is a good choice, as it contains organic matter which is both nutrient and mineral-rich. You can also purchase a special soil mix for terrariums. These soil mixes are usually enriched with vermiculite or volcanic sand, which are great growing mediums too.

Of course, the best part about making a terrarium is being able to decorate it according to your own taste. Have fun landscaping your terrariums with fine stones and figurines, to give it a personal touch! With that new-found satisfaction in seeing your final product, you will be more likely to take care of your new beloved terrarium better.

If you ever stop to peer into a closed-jar terrarium, you may realise that the survival of the plants within is based on a self-sustaining ecosystem. The ecosystem within the terrarium is a simplified version of the major ecosystems on our planet Earth.

Water within a closed-jar terrarium is first taken in when you spray water at the plants. These water droplets run down the inner surface of the terrarium into the soil. These terrarium plants absorb water in the soil through their roots. Water in the plants move up from the roots, through the stem and eventually into the leaves. Some of the water is also lost through the leaves via transpiration, contributing to the water vapour in the environment of the terrarium. This water vapour then condenses, runs down the inner surface to the soil and the cycle is repeated. This is mostly the reason why you will always see water droplets in the inner walls. Hence, the water inside is continuously being circulated, just like the water cycle we learnt about in school.

These plants would need to be adequately exposed to sunlight for photosynthesis to occur. Photosynthesis is a chemical reaction which occurs in plants to produce sugar and oxygen. This reaction also requires the presence of the sun, carbon dioxide and water. So where does the carbon dioxide in a closed-jar terrarium comes from? At night where there is no sunlight, respiration will predominantly occur in these plants. Oxygen is taken in by the plants, and carbon dioxide is produced. In the day, the carbon dioxide is taken in during photosynthesis, and the oxygen is replenished. Hence, photosynthesis and respiration maintain the balance of oxygen and carbon dioxide within the terrarium. Don’t these processes remind you of the trees in our forests? These spontaneous processes allow for the survival of the terrarium plants in its mini-ecosystem, very much like the self-sustaining ecosystems of our planet Earth.

Who would expect that the unassuming terrarium is like a miniature version of Earth? For more help on how to care for some of the common houseplants, check out the rest of our articles in this blog!

Fittonia – Also known as nerve plants due to their nerve-like striations on their leaves, these plants are a great fit for terrariums due to their low-growing height.
Succulents – These are plants with fleshy and thickened parts, to retain water better. Their unique appearances make it them a favourite as terrarium plants.
Air plants – Also known as Tillandsia plants, they obtain most of their nutrients from the air around them. Caring for them usually involves misting or soaking them in water for short periods of time.
Sphagnum moss – These mosses have high moisture-holding capabilities. Using it as a terrarium barrier layer allows for the plants to grow without oversaturation in water.
Vermiculite – A naturally-occurring mineral which can be added to the soil, to create favourable growth conditions for plants during gardening

Written by Nasiruddin
Illustrations by Toh Bee Suan


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