You want to decorate your home or office with a terrarium, but admittedly, you’re new to the world of terrariums. Given the size constraints of a terrarium, the last thing you want to do is to accidentally choose a plant species that outgrows its environment. Which terrarium-friendly plants stay small?
What are the best small plants for open terrariums? The best small plants for open terrariums are as follows:
- Air plant
- Mini African violet
- Minimus aureus
- Golden clubmoss
- Baby tears
- Nerve plant
- Watermelon peperomia
- Zebra cactus
- Venus flytrap
- Hen and chicks
- Living stone plant
- Marimo moss balls
Are you curious about the size of these various plant species at maturity or what their care requirements are? Ahead, I’ll share all that information and more. By the time you’re done reading, you’ll confidently be able to choose which small plants would be best for your open terrarium!
13 Exceptional Small Indoor Plant Species to Fill Your Open Terrarium
When it comes to microscopic, delicate indoor plant species, the air plant or Tillandsia takes the cake.
Although this plant has been known to grow 7 feet tall in some conditions, the average size of the air plant is more like 2 inches, with some bigger, healthier ones reaching heights of 5 inches.
Since it’s so small, anything but occasional bright, indirect light could torch the air plant to dust. When watering this plant, you have a few options.
You can try soaking your air plant in water and see if it likes that. Other indoor gardeners finely mist this plant from time to time so as not to overwhelm it with water.
Mini African Violet
If you’ve read this blog, then you’re surely familiar with the regular-sized African violet, but what about the mini version? This smaller plant species takes everything you love about the standard African violet but shrinks it to a containable size of 6 inches at maturity.
Before you ask, yes, your mini African violet will still grow flowers, but not necessarily purple ones. The Morgans Declan Duff cultivar has white and lavender flowers and the Robs Soliloquy baby pink flowers.
Don’t give the mini African violet nearly as much light as you’d provide for its full-sized counterpart. Indirect, bright light works well, as this plant needs light to bloom.
When it comes to watering requirements of the mini African violet, you’ll want to minimize the water quantities too. It becomes even more important to water your mini African violet using lukewarm water.
Sure, any plant with the name “spider” in it might give you the heebie-jeebies, but the spiderwort shouldn’t. The Tradescantia grows beautiful flowers in various shades of purple, making it an elegant complement to the mini African violet.
Even better is that this particular plant is completely manageable for terrariums at a smaller size, as the spiderwort only grows to around 6 inches.
The spiderwort does best in loamy potting compost or a soilless mix, not regular soil. It needs filtered but bright light and periods of partial shade here and there.
Another feature of the spiderwort that makes it one of the best small plants for open terrariums is the amount of water & humidity it can endure. You can water the spiderwort a bit more hardily than your other small terrarium plants without causing root rot.
Terrariums look best with a variety of plants, so my next recommendation is actually a grass called the Minimus aureus.
If that name doesn’t already give it away, this indoor plant species is nice and tidy for your terrarium, reaching an average height of 3 or 4 inches with slow growth along the way.
The foliage color of the Minimus aureus can range from green to yellow to a variegated combination of the two so don’t panic if your Minimus aureus is yellow or turns a shade of yellow over time. The best conditions for this grass species are moist to wet soil (some shade is okay but too much inhibits growth) and indirect, bright light.
From grass to moss (and not the only moss on this list), golden clubmoss will jazz up your indoor terrarium too. Also called spike moss because of its rather prickly texture, the Selaginella kraussiana grows between 2 and 4 inches tall when fully matured.
Golden clubmoss can get quite long width-wise if given the chance, but I don’t think that should be an issue in your small terrarium.
The abovementioned Selaginella is the standard cultivar in an appealing greenish-gold hue. You can also add the Variegata to your indoor garden, which is known as the frosty fern.
Why is golden clubmoss plant called the frosty fern?
It gets its name from the distinct white tips on the clubmoss’ leaves.
Despite that it’s a South African native, golden clubmoss cannot handle direct sun. The golden clubmoss does really well in indirect light.
When it comes to watering your golden clubmoss, make sure to leave some of the soil moist. Be sure not to soak the soil like you would when growing a Minimus aureus.
As for humidity, one of the reasons the golden clubmoss does so well in terrariums is because it thrives in high humidity environments. 50 percent relative humidity or higher is what it loves to be in so placing it on along the inside glass wall of your terrarium is a great place to put it.
For more about indoor plants that love humidity you’ll want to read: Which Indoor Plants Like Humidity?
Yet another fantastic pick for your open terrarium is the Soleirolia soleirolii or baby tears. This plant with its delicate, dangling vines grows to heights of around 4 inches tall but can get far wider in large containers such as a pot or hanging basket.
Like the clubmoss, baby tears shouldn’t grow wildly outside of their environment. If they do, a bit of pruning can help.
Bright, filtered light is best for baby tears, but some direct sun surprisingly won’t damage this plant. Give the baby tears water often, anytime the soil begins to dry. If your plant has wilted, then you’ve waited too long to water it.
With the right care routine for your baby tears, you might just see yours bloom small but beautiful white flowers.
Are you looking for an indoor plant that can act as the centerpiece for your open terrarium? I think you’ve found it in the nerve plant or Fittonia albivenis.
Don’t just settle for a green nerve plant when you have so many exciting cultivars to choose from. Depending on the variety, you can own a nerve plant with pink/maroon leaves and green veins or one with green leaves and electric pink veins.
I also personally like the dark red nerve plant, as it looks like a whole different species.
The nerve plant reaches heights of 3 to 6 inches, so it’s perfect for a small terrarium. To care for yours, increase the humidity, provide indirect but bright light, and water when the soil gets just a bit dry.
Watering is a big deal with the nerve plant, as this species can collapse if it’s too dry. Personally I like when my houseplants are able to indicate that they need more or less of something.
That said, keep an eye on the posture of your nerve plant and be sure to water it at the first sign of it’s leaning to one side.
Fans of variegated plants will be happy to hear that the watermelon peperomia grows nicely in open terrariums. The plant, despite being a peperomia, doesn’t reach heights of 12 inches like most peperomias do.
The watermelon peperomia grows to a height of 6 inches, perfect for a small terrarium.
The dark green stripes against the lighter green leaves of the Peperomia argyreia are the characteristics that give the watermelon peperomia its name. This peperomia has been known to grow green flower spikes in the summer at times.
To get to that point, water the peperomia when its soil dries out but no more often than that. Bright, indirect light will protect this peperomia’s variegation.
Continue changing up the textures of your open terrarium with the Haworthia attenuata or zebra cactus. The blade-like leaves of this succulent feature horizontal grooves in a lighter hue that do indeed resemble zebra stripes.
You’ll just have to look up close to see the “stripes,” as the zebra cactus only grows to roughly 6 inches.
The zebra cactus does well in indirect light just like most of the plant species in your open terrarium. You might think that’s a tad confusing since the Zebra Cactus is a succulent, but due to its small size, it can easily burn if it’s placed in direct sun.
Succulents retain water in their leaves, so skip watering this part of your terrarium for a while and the zebra cactus will be fine.
When it comes to growing a zebra cactus in a terrarium the humidity in the terrarium will do most of the watering for you
You’re probably wondering how you can integrate a Venus flytrap with your other indoor terrarium plants. I wouldn’t worry about it too much, as the Dionaea muscipula is a meat-eater, not a plant-eater.
And as for the size of a Venus Flytrap, the average diameter of this excellent terrarium plant is just 5 to 6 inches, with each trap about 1.5 inches.
When it comes to the watering habits of a venus flytrap growing in a terrarium, water your Venus flytrap frequently and with distilled water.
You never want to let its planting mix dry out either. I wouldn’t put it near any of your terrarium plants that are sensitive about how much water they get.
Otherwise, the other facets of care apply, such as average room temperature and indirect, bright light. It’s just the watering habits of this carnivorous plant.
The venus flytrap is indigenous to the subtropical wetlands on the East Coast of the United States in North & South Carolina. So you can see where its love for water comes from.
If your Venus flytraps’ traps become brown or black, you need to prune them; the same is true of the flytrap’s leaves.
Hen and Chicks
Wait, hen and chicks? You thought we were talking about terrarium plants, not animals. Actually, I am!
Hen and chicks or Sempervivum tectorum is a succulent species that grows a dense mat like the Minimus aureus and golden clubmoss. Its height is perfect for terrariums, between 3 and 6 inches, although its width might be around 6 inches too.
Why the hen and chicks name?
It’s not random, the chicks are mini rosettes that sprout off the hens or larger rosettes, which are the parents. Now it makes more sense, right?
Unlike most of the plants on this list, hen and chicks is fine with full sun. A bit of shade here and there shouldn’t affect growth much, but the more sun this particular succulent gets, the more colorful it becomes.
Water infrequently and leave your home or office’s humidity where it is. If you’re comfortable with the humidity in your home than so are they. Hen and Chicks are easy going terrarium mates when it comes to living in a glass bowl together.
Living Stone Plant
For some truly great variety in your open terrarium, you must have a few living stones or Lithops. I know, these don’t look like plants at all, just tiny, colorful rocks. That’s the charm of the living stones.
That and the brain-like texture and shape these succulents are known for.
Each stone is about half an inch to an inch tall and maybe 3 inches wide at its largest. The whole point of living stones is to stay low to the ground so they don’t drink in too much heat or sun, neither of which they really care for.
If your Lithops split open at the seam, it’s nothing abnormal. At that point, increase your watering frequency, but still only do so about every 10 days, maybe every two weeks if you’re really pushing it.
Watering your living stone in the summer is a no-no, which may seem counterintuitive, but isn’t.
Marimo Moss Balls
The last, but not least, exceptional Small Indoor Plant for an open terrarium is the Marimo moss ball. The Aegagropila linnaei features a smooth, velvety texture.
They naturally grow in rivers and lakes across Northern Europe and Japan. An average moss ball may have a diameter between 1.75 and 2.25 inches. At that point, they could be as old as 15 years!
Marimo moss balls do well submerged in water, but in an enclosed space, they can survive for a bit without water. Do make sure your terrarium is closed if you want to grow Marimo moss balls without an area with enough water for your marimo moss balls.
Medium, indirect light will help the Marimo moss balls keep their bright green hue. And if your marimo moss balls turn brown, it’s likely due to how little light they’re receiving, so consider moving your terrarium closer to its light source.