How Long Do Terrariums Last?

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The terrariums that make the news and seem to capture our interest are those sealed ones that can last years without being watered.

They are cool, I grant you, and not having to do any maintenance is appealing, but for me, it removes a few of the benefits of having terrariums (they’re awesome for rehabbing, propagating in, and releasing predatory bugs into).

A ‘normal’ terrarium can last just as long – or longer – than a sealed one.

The problem we have here is that we only really have records that terrariums existed from the early 1800s, and they weren’t really a mainstream hobby until the 60s.

How old is the oldest terrarium?

This is interesting. When I first started researching terrariums, David Latimer cropped up a lot as the owner of the second oldest sealed terrarium. The terrarium was made in 1960 and was last opened in 1972.

Latimer claims that the plants just grew to the size of the bowl which is cool.

It also makes me a bit sad, because it reminds me of when people claim that goldfish grow to the size of their tank. What actually happens is the goldfish stops growing because the space isn’t big enough, and becomes stunted and unhealthy. Goldfish belong in ponds, people. They’re freaking carp.


Back to the story.

So when I returned to my research a few months later, Latimer now has the oldest sealed terrarium.

He used to have the second oldest.

It’s the same terrarium.

We seem to have lost a terrarium.

Which is fine. I mean, someone could have dropped it. Accidents happen all the time.

But there’s no record of it anywhere

I have no idea what happened there, but I like to think that there used to be a large part of the internet dedicated to the world’s oldest sealed terrarium, then the guy dropped it, and resolved to remove all traces of its very existence from the web.

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Do terrariums have a lifespan?

No, not really. As long as someone is looking after it, a terrarium should last for as long as you want it to.

Provided you build it properly, and don't try to keep a jade plant in sphagnum or something. I have an article here on setting up a really cool terrarium.

It’s really a case of Theseus’ ship. Various parts of the terrarium will need to be replaced over time, but there’s no lifespan on the whole thing. I recently moved my terrarium into a bigger tank, but it still feels like the same terrarium.

You know how some people inherit Hoya or Christmas cacti from their relatives? I think you could definitely leave a terrarium.

I don’t actually know how long David Latimer’s terrarium will last. He seems to have the water and oxygen cycles down pat, so I can’t think of a reason why it would die EXCEPT sometimes stuff happens. Perhaps a bacterial bloom could cause a spike in…something and the whole thing comes crashing down.

But you don’t need to seal your terrarium. Put a lid on it SURE, but you can still go in and prune and move stuff around etc. I like to buy baby Calathea and grow them on in my terrarium, and take them out when they’re bigger. It’s also a marvellous environment in which to root cuttings.

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How to keep your terrarium alive for longer

  • Pick appropriate plants

Don’t go for succulents or air plants they will hate it and then rot. Instead go for plants that people consider hard to keep alive – ferns, peace lilies, calathea. All those plants that you didn’t buy because you don’t have the humidity.

  • Learn how to care for it

You don’t water terrariums like you water potted plants. I have an article here on watering terrariums, but the long and short of is that you mist them frequently, or get a fogger to do it for you. You’ll also need something to stop mold growth – charcoal is popular, but we went for a population of springtails.

  • Know your limitations

The glass is another barrier to the sun, so your inside terrarium might be slightly darker than the rest of the room. Can you put it in a window? Would you be willing to put up grow lights? If not, you need to pick plants that won’t mind a bit of lower light.

  • Keep on top of pests

Aphids are the worst for terrariums, but they’re also easy-ish to treat because it’s an enclosed area. We have a frog to eat them, but obvs he requires a tonne of additional care.

As I mentioned before, you can get pest-eating bugs such as ladybird larvae to eat your aphids.

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How to make sure you pick the right plants for your terrarium

I have an article about plants that like terrariums, but it depends a lot on the size you’re going for. We have a bit terrarium, so I have things like Aglaonema and Rhapidphora tetrasperma in there. You could go for smaller plants like fittonia and Begonia amphioxis.

Make sure you pick a plant that can handle (and thrive in) the humdity. Succulents are highly unlikely to thrive, even if you could get enough light for them. Snake plants would be miserable in a terrarium, as would crotons.

In the beginning, stick to plants that definitely love damp, rainforesty conditions, and over time you can graduate to trickier things. My next project is to grow a hoya in our terrarium. Hoya are known to prefer to dry out a bit, but in the wild, they live in humid areas. I’m gonna try and grow one epiphytically, more like how they’d grow naturally. How cool would Hoya blooms look in a terrarium?!

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How do you build a self-sustaining terrarium?

From what I’ve read, the trick to building a sealed terrarium is to unseal it as often as required. It isn’t a case of building a terrarium, sealing it, and then never opening it again. You have to troubleshoot at first, and somewhere along the line, you realise you haven’t opened it in twenty years.

You may need to add more water if the plants dry out, more carbon if mold starts growing, and more plants if you get algae on the glass.

I highly doubt you can get all the ratios right on the first go.

A terrarium doesn’t have to be sealed to be self-sustaining. With the right equipment, you don’t really need to do a lot to maintain your terrarium.

We have a big terrarium and put small plants in it. That cuts down on pruning right away.

  • We have lights on timers, so they come on around noon, go to a dusk setting around 8 and go off around 11
  • We have a fogger that goes on for half an hour 3 times a day (this is new, so we may adjust it) so we don’t need to water – we do need to keep the fogger topped up with dechlorinated water though
  • We have a clean-up crew of springtails and isopods to eat decaying matter. The frog ensures the populations don’t get too big. Also, a large amount drowns in the water dish. It’s only 1cm deep so I think that’s just natural selection.

Doing a terrarium this way may seem like more hassle (and it is) but most terrariums aren’t sealable. If you want a sealable terrarium, you’re massively limited by the plants you can have. You’d need the terrarium to be pretty full to stop algae, and you’d need plenty of small eaves so they dropped often and rotted to produce nutrients and carbon dioxide. You couldn’t make a beautifully sculpted scene of fittonia and begonias because those plants wouldn’t be able to self-sustain themselves. Your best bet would be something viney with small leaves, like a tradescantia. You might be able to manage a maidenhair fern, but I don’t know how that would work. It might be fun to try actually.

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Threats to the longevity of your terrarium

  • Mold – not threatening in itself, but if it thrives it will end up taking over and weakening or killing your plants. Make sure you add charcoal/carbon to your soil. If you see mold, add more.
  • Rot – I recommend starting your terrarium with damp soil and then spraying it down NOT watering it with a watering can to prevent the soil from ever getting too wet. The high humidity means your plants don’t need to be thoroughly soaked like your regular house plants.
  • Letting it get overgrown – keep your terrarium pruned back. If it gets too thick water can get trapped and you can end up with rotting leaves.
  • Low light – I recommend adding a grow light to your terrarium, because it’s a great way to both improve the health of your plants AND show off your terrarium better. I use these.
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And that’s it for today! If anyone has an insight on what happened to the original world’s oldest terrarium, I’d be really interested to find out how it was usurped.

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