Terrarium Up Close - Light and Shade

We find that…

this is the concept that is the hardest to grasp among the 3 topics we cover. In a nutshell, the terrarium we build here at InOut Atelier must be kept indoor, and away from direct sunlight. It’s a golden rule I find myself repeating over the years, and will continue to do so for the many years to come (lol). For those who have been to our studio, we even showed you what happens when they are left long enough under direct sunlight.  They completely dry out (overtime) and the mosses turns yellow. (*They basically look something like that on your left.) This terrarium is firstly not a 100% sealed terrarium, there are no rubber underneath the lids, which means moisture and humidity escapes. Secondly, we left it under direct sunlight due to negligence. In fact, this terrarium was growing very well before it was met with this fate. If you were to observe carefully, you could see that the mosses grew and engulfed a fence figurine and a small pebble at the mid ground level.

So why and how did this happen?

Fortunately, and ‘unfortunately’, light and heat comes as a package in the form of natural daylight. Terrariums in general is a mini green house. They absorb light and retains the heat. When they are left under direct sunlight, the intense heat from the sun will cause the inside of the terrarium to feel like a sauna. Just imagine how it must have felt like being trapped inside a glass house under the scorching heat, now, imagine how a delicate and fragile life form would have been in the same scenario. It’s a one-way ticket for this case.

So how much light and shade is needed

To clarify, light is actually good for the mosses and plants in a terrarium. The brighter it is the better the plants can generate food for themselves through chlorophyll. And chlorophyll is the natural compound found in a green plant that give them their colour. But humans can’t really perceive light very well as compared to other beings such as animals and even plants.

We have special photoreceptors to determine light and will react accordingly to its intensity and colours. In general, we see limited amount of wavelength while plant on the other hand, has photoreceptors that allow them to see more wavelengths. Therefore, we don’t really know if the terrarium is receiving enough light or not base on our naked eyes.

We found this really cool illustration by Leon & George online depicting the different light level that is shone into a room. We understand that not everyone has a light measuring device to measure the amount of light that is coming into their space. But a good general rule of thumb is to put them in bright indirect light to medium light area. Area that are closer to windows but without the light hitting on the terrarium directly (this includes the morning and evening sun by the way).

What happens when there is too little light, and too much shade?

Sometimes, our advice to keep them away from direct sunlight got taken too literally, and client ends up keeping them in perpetual darkness.

When the mosses do not get enough light to go through chlorophyll for a prolong period of time, they will start losing their green pigment and turn dull, almost looking malnutrition. It will affect the overall aesthetic of the terrarium and needless to say, the condition of the mosses. If you have to place the terrarium in a spot that denies them the light that they need, the very least you should do is to purchase a light source for your terrarium. We do offer them on our webstore here if you’re keen. They are not the best option, but its an option that will help sustain your terrarium nonetheless.