Honestly, lighting for terrariums is the most overlooked / misunderstood issue I see in terrarium care.
Watering for example, is something that everyone is at least mindful of. Whereas lighting is one of those things that you generally don’t know that you don’t know.
It’s not just you, we’re simply not designed to eyeball good light conditions.
And, we all know that direct light is the bane of tropical plants – so we often undershoot lighting with our terrariums… by a lot.
In this guide, I’ll take you through the practical steps of choosing the right spot for your terrarium, and how to choose a grow light if you want an easy life.
Let’s do it!
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Understanding Terrarium Light Requirements
Lighting is an essential part of terrarium plant care. It’s arguably the main driver of plant health and to be frank, we’re not biologically built to interpret it effectively.
Our eyes are designed to adapt to lighting conditions, not to quantify them. What looks bright to you is not necessarily bright to a plant.
Plus, we’re not particularly good at communicating it either.
What exactly does “partial shade” mean to you?
In reality, terrarium lighting is relatively straightforward on a practical level, but one of the more difficult care requirements to master.
This is especially true of artificial lighting, i.e. grow lights.
Any LED grow light near a terrarium is most likely going to do the trick (provided it’s a regular size).
But, if you’re trying to fully optimize a system or looking to light a particularly large or complex container – then it becomes a lot more complicated and… mathematical.
I know (internal scream).
Truth be told, terrarium lighting is a deep rabbit hole if you really want to dive into the science behind light brightness, intensity, absorption, etc.
So, on a whole, I prefer to keep things as practical as possible.
The Best Natural Lighting for Terrariums
Sure, low-light terrarium plants do exist, but that’s often taken too literally.
Low light does not equal no light.
As true terrariums grow plants of a tropical nature, it’s natural that they should thrive in conditions that mimic that of their natural rainforest environment.
This can be simply expressed as bright indirect light.
It’s what I call the “tropical gold standard,” but let’s be honest – it doesn’t paint a very clear picture.
So, here are a couple of practical ways to achieve this:
- Choose the right spot in the home – The location of your terrarium is critical in supplying it with adequate lighting conditions. The direction of the window and its proximity to the plants are the main factors, but the time of year, the weather and your location all play a part.
- Filter natural light – Strong direct light can quickly scorch delicate terrarium plants, but if you’re able to put up a screen or some blinds, then you can weaken those rays to a healthy intensity.
Assuming you’re in the Northern hemisphere (like myself), this is how I’d approach the window situation.
- North – This is the ideal spot. Northern-facing windows never see direct sunlight and enjoy indirect light throughout the entirety of the day. Feel free to put your terrarium as close to the window as possible (i.e. on the windowsill) to maximize the amount it gets.
- East – The next best, East-facing windows receive some weaker direct sun in the morning, then bright indirect light throughout the day.
- West – West is a little risky, with your terrarium seeing some strong full sun in the afternoon. Delicate plants should be shielded, and realistically only the more tolerant plants will do well here.
- South – South-facing windowsills are pretty much a no-go I’m afraid. Your terrarium will experience full sun throughout the hottest parts of the day. In rooms with a South-facing window, you’ll need to move your terrarium several feet away from the light source.
Terrarium Grow Lights
If you have a typical tabletop terrarium, then any sort of grow lamp will do.
Personally, I don’t bother with the multi-colored purple and blue lights. Any benefit for the plants is marginal and I find the lighting unsightly and jarring.
White light has everything a plant needs, and let’s be honest, it’s what we want to illuminate our home with.
Grow lights tend to be on the harsher side than warmer, but it’s the nature of having light that’s intense enough to produce growth.
I use a relatively inexpensive Sansi grow bulb that I purchased from Amazon that’s fitted into an Ikea lamp. Nothing fancy!
LED Terrarium Lights
For those with a “tank” setup, an aquarium light is an easy fit.
They’re typically strip lights designed to hook onto the side of an aquarium tank. Being a bar, they can illuminate evenly down the full length of the container.
Generally, any aquarium light should do the trick. Finding the one that fits best is usually the challenging part.
That’s where a brand like InSitu Ecosystems comes in handy.
Their range of modular vivariums can be purchased with an integrated LED lighting system. No awkward cables or connections to sort out, just a seamlessly integrated vivarium unit.
Lighting planted vivariums for the benefit of animals is a very different ball game, and perhaps the most challenging to fully understand.
In addition to the typical growth conditions, you’ll also likely need to consider unique day-night cycles, basking light and temperatures, thermal gradients, and the creation of shaded areas.
For these reasons, I’m afraid I can’t advise on any of these in this article.
There’s too much to cover and they’re ultimately unique for every animal setup.
Over to You
Do you struggle with getting the right lighting for terrariums?
Let me know in the comments.