Closed vs Open Terrariums
A closed LAB Jar Terrarium — a sealed, self-sustaining tropical world
"Terrarium" covers two quite different things in our store, and knowing which one you've got — or which one you want — makes all the difference to how you care for it. Here's how closed and open terrariums compare.
Closed terrariums: a sealed, self-sustaining world
A closed terrarium lives inside a lidded jar, globe or egg vessel. Once it's built and settled, it's a genuine miniature ecosystem — moisture, oxygen and carbon dioxide circulate inside the sealed glass, with condensation forming, falling back to the soil, and being taken up by the roots again. That cycle is why a closed terrarium needs so little from you: in our own experience, a well-settled one might only need watering a couple of times a year.
We only plant closed terrariums with species suited to that humid, enclosed environment — things like Fittonia, bun moss, Ficus Ginseng and Chamaedorea palms. The job is mostly observation rather than routine care: keep an eye on the moss colour and leaf condition, and only reach for water if the soil and moss genuinely feel dry to the touch.
The lid is what makes a closed terrarium work — it's also why we say never to mist one. Adding extra water on top of an already self-watering system is the most common cause of mould and rot.
Open terrariums: a planted scene without the lid
An open terrarium — think a succulent garden in a glass bowl — has no lid and isn't sealed, so it doesn't build up that internal humidity cycle. It behaves much more like a regular potted plant: water evaporates rather than recirculating, so it dries out and needs topping up on a normal watering schedule rather than once or twice a year.
Because there's no humidity trap, open arrangements suit plants that prefer drier air and free-draining soil — succulents, cacti and similar dry-tolerant species — rather than the moisture-loving plants we use in closed jars. The open shape also makes them easy to tend day to day: there's no lid to lift, and you can deadhead, top-dress or rearrange the piece whenever you like.
At a glance
- Closed: sealed jar with a lid, self-watering ecosystem, watered rarely, planted with humidity-loving species like Fittonia and bun moss, never misted.
- Open: no lid, dries out and waters like a normal houseplant, suits succulents and cacti, easy to tend and rearrange whenever you like.
Which one suits you?
If you like the idea of a living scene that mostly looks after itself, and you're happy to leave it be for long stretches, a closed terrarium is hard to beat — it's also the better choice if your home runs dry or centrally heated, since the sealed glass holds onto moisture regardless. If you'd rather have something you can water, prune and restyle more hands-on, or you're drawn to succulents and cacti, an open arrangement will suit you better.
Whichever style you prefer, we can help you find the right one.
Leave a comment
Comments will be approved before showing up.