Care Guide — Tiny Botanica

What is a terrarium and how do they work?

The name terrarium comes from the Latin “terra” meaning earth or land and were widely used in the scientific community for growing and transporting rare plants from the 1840’s. Closed terrariums are perfect for tropical plants and mosses as they mimic the natural conditions tropical plants love, and create a (mostly) self-sustaining ecosystem.

These tiny worlds operate much like our Earth does - as the plants transpire, the jar acts like our atmosphere would, and holds moisture and warmth in the system, supporting life inside. The water vapour released by the plants condenses on the glass, watering the plants inside. This is only possible if you keep that lid closed though! So, have the occasional peek, and do any maintenance you need to but otherwise keep that lid tightly closed.

What is inside your terrarium?

We love sharing how these amazing little worlds work. Take a look at the layers inside your terrarium and how they work together to sustain life.

Plants: Duh! We use tropical, moisture loving plants that enjoy the conditions inside a terrarium. These include lots of types of ferns, air plants, fittonias, orchids and cute little things like Spikemoss.

Moss: These ancient little guys date back a whopping 450 million years well and truly pre-dating the dinosaurs! They are a beautiful addition to the ecosystem inside the terrarium.

Soil: The soil we use is a manufactured high-quality potting mix produced by our friends at Rocky Point. It is 40% coconut fiber which is used to hold in that moisture and provide a open, fertile medium for the plants. It is also already fed with all the fertiliers the system will need for the first 14 months of growth.

Spagnum moss: Used for its superior water retaining properties, spagnum has a stable pH and helps keep the terrarium moist but gives allows plenty of air through to the plant’s roots.

Charcoal: Horticultural charcoal is a clean, stable product used to promote air flow in the system, stablise the pH and helps ward off unwanted bacteria and mould in the system.

Gravel: Because the jar doesn’t have a hole for excess water to drain through like a plant pot does, we put gravel in the bottom to act as a drainage layer. Excess water filters through the layers and settles in this layer at the bottom of the jar. You can reference how much water is sitting in this little reservoir and gauge how frequently (if at all) you need to water.

Terrariums are terrific little low-light companions, but that does not mean no light.

Your terrarium needs bright indirect light - basically bright enough that you could comfortably read a book but not feel the warmth of the sun on your skin. Alternatively, stick out your hand and have a look at the shadow it casts. The shadow should be weak and blurry, not a crispy outline of your hand.

Remember it is essentially a tiny greenhouse, and that the heat can’t escape the container so we want to ensure the plants aren’t getting scorched.

You may have to move it throughout the year as the light changes, for example a northern window in summer is perfect but come winter it would be receiving too much direct light. Play around with the placement and keep on eye on how it reacts to where you have placed it - are the plants looking plump and perky? Are they becoming leggy or searching for light? Is all the growth happening on one side of the terrarium? Is the foliage getting burnt and dying off?

Light requirements

Water requirements

Watering can be a sticking point for first time terrarium parents. Just as not watering can kill plants, so can too much water.

The beauty of terrariums is that they can often go months without watering, so before you whip out the watering can consider:

Drainage layer - the easiest cue of how your terrarium is travelling for water is the level of water sitting in the drainage layer. You can have a little there but you only want minimal pooling.

Condensation - there is supposed to be high levels of condensation on the glass during certain times of the day. If the glass is always fogged up, the environment might be too wet, and conversely if you aren’t seeing any condensation it might be time for a water.

Foliage - keep an eye out for wilting foliage, discolored foliage or greying foliage as that may signal thirsty plants. Just to be confusing though, if the foliage is rotting and falling apart it is probably too wet.

Soil - you want the soil to be moist but not sodden. You can check this by getting in there and giving it a feel, or if you’re not that keen, poke a chopstick down into the soil and inspect the soil that is stuck to the stick when you remove it.

We recommend watering with purified water where possible to avoid heavy water build up inside the terrarium (filtered, rainwater, demineralised etc). It can be easier to water by misting the terrarium with a squirty bottle little bits at a time, especially an established terrarium, as it reduces the risk of overwatering.

Maintenance

Pruning is as much about keeping your terrarium healthy as it is about keeping it pretty. Foliage will naturally die as the plants age so be sure to remove any dead or diseased foliage as soon as you notice it.

Keep an eye on plants growing against the container or growing too tall for the container. As the plants grow, they may become too thick and bushy for the smaller plants and mosses, so thin out foliage to ensure all plants are getting enough light.

You may also want to prune and sculpt the foliage in the terrarium in order to style it. Pruning plants as they grow will help preserve a sense of scale and style in the terrarium.

Pruning

Keeping the glass of your terrarium clean ensures the plants are getting as much light as possible, and keeps the terrarium looking sparkly. We recommend using clean paper towel, and making sure you aren’t using any cleaning chemicals in or on the terrarium. You can periodically clean the condensation however this is not necessary.

Cleaning

You terrarium has enough food and nutrients for the first 12 months in your home. After that, you can add a small amount of a complete slow release fertiliser to support your plants. You can also water with a very low dose of a liquid fertiliser such as a seaweed solution occasionally should you wish, however use sparingly.

Fertilising

Weeds

Just like in your garden, unwanted little weeds may pop up from time to time. Whilst all care is taken to ensure all the products we use are sterile and free of weeds, some of the elements we use are wild foraged and weed seed may be present. Don’t fret, this is easily dealt with - simply pluck out any unwanted plants and dispose of appropriately.

Things to watch out for

Like the plants in the terrarium, mould also thrives in hot and humid environments. Mould and fungus naturally pops up, and plays an important roll in the soil. It shouldn’t affect healthy plants, but we also don’t want it to take over in there. There are a few options to deal with mould and fungus depending on what you’re experiencing.

Increasing the airflow and drying out the terrarium often helps. If you’re able to leave it with the lid off in a protected spot for a couple of weeks you might find it goes away on its own. Sometimes these things just need to run their course.

If that’s not you style, you can spot treat with some hydrogen peroxide by applying with a cotton bud to the inflicted area. Spraying the terrarium occasionally with chamomile tea has also reportedly works as a natural fungal treatment.

Mould and fungus

Your terrarium should have a nice damp earth smell. If it starts to smell funky, there is something going on. Have a close inspection - is there a moisture problem? Is there a mold problem? Is there decomposing foliage? If you can’t identify an obvious problem, leave the lid off in a safe sheltered spot for a few hours and see how the terrarium reacts and whether the smell improves.

Smell

Have more questions? Check out our FAQ’s for more terrarium knowledge nuggets.

Slow down. Take a deep breath. Enjoy your precious tiny world.