Terrarium Making | Hobby Portal

Q: Can I use a reused jar?

Yes. A clean, intact wide-mouth jar works well for a first build. Check for cracks and sharp edges, and make sure the opening is wide enough for your hand or tools.

What Terrarium Making Is

A terrarium is a glass or clear container planted as a miniature landscape — the land-based counterpart of an aquarium. In this hobby you build a small scene from substrate layers, hardscape (stones, bark, wood), and living plants, then manage the light, moisture, and airflow that keep it stable. A beginner’s first session is mostly hands-on craft: washing the container, layering drainage and soil, planting a few small plants, and arranging the scene. The ongoing work is observation: reading condensation on the glass, trimming overgrowth, and adjusting watering.

The distinctive feature of a closed terrarium is a small internal water cycle: moisture evaporates from the soil, condenses on the glass, and drips back down, so a well-built closed system may need watering only every few weeks. That is real, but it is not “self-sustaining” — the plants still need the right light, and the system still fails if the balance is wrong.

The practice descends from the Wardian case. In the late 1820s, London physician and botanist Nathaniel Bagshaw Ward noticed ferns and grasses thriving in the soil of a sealed jar where he had kept a moth pupa, and in 1833 he shipped British ferns in a glazed case to Sydney, where they arrived alive. His 1842 book On the Growth of Plants in Closely Glazed Cases popularised the method, and ornate Wardian cases became a Victorian parlour fixture.

Terrarium making splits into a few different activities that share the same containers:

Closed tropical terrariums — the classic sealed jar with moss, fittonia, and small ferns. The best first project for most beginners.
Open terrariums — bowls and dishes for drier plants, including succulents and cacti.
Bottle gardens — narrow-neck bottles that require long tools and patience; a later project, not a first one.
Bioactive displays — tropical setups that add springtails or isopods as a “cleanup crew”; a step up that adds invertebrate welfare to plant care.

Who It Suits

Terrarium making suits people who like plants, miniature landscapes, and compact hands-on projects. It is a good fit for small homes, desks, and shelves, and for anyone who wants a plant hobby with more design work than ordinary houseplant care. The work is seated, mostly quiet, and a first build can be finished in a single afternoon.

It is less ideal if you want a completely maintenance-free object. Even a closed terrarium needs the right light, a moisture balance, occasional trimming, and attention to mould or struggling plants. It is also a poor fit if you cannot provide bright indirect light: dim corners lead to weak growth and rot.

Getting Started

Choose one simple style before buying materials. Closed tropical terrariums suit mosses, fittonia, small ferns, peperomia, and other humidity-loving plants. Open terrariums suit drier arrangements, but many succulents and cacti do better in open dishes than sealed jars because they need airflow and careful watering.

For a first project, use a wide-mouth clear container with an opening large enough for your hand or tools. Build a small layout with a drainage layer, a thin layer of activated charcoal, suitable potting mix, two or three small plants, moss, and one focal piece of hardscape such as bark, wood, or rock.

A sensible learning sequence:

Build one small closed tropical terrarium and keep it stable for a month.
Try an open dish garden with drier plants, so you learn both moisture regimes.
Only then attempt a narrow-neck bottle garden or a bioactive setup, both of which are harder to build and harder to fix.

Key Terms and Techniques

A handful of words do most of the work in terrarium kits, workshops, and online guides:

Hardscape — the non-living scene elements: stones, bark, driftwood, gravel. Placed before planting and hard to move afterwards.
Drainage layer — pebbles, LECA (expanded clay), or coarse grit at the bottom that keeps roots out of standing water.
Activated charcoal — a thin layer that helps keep the substrate fresh and reduces odour and rot in closed systems.
Substrate — the growing medium. A standard potting mix works for tropical closed terrariums; cacti and succulents need a fast-draining mix.
Condensation cycle — in a closed container, soil moisture evaporates, condenses on the glass, and returns to the substrate. The amount of fog on the glass is your main moisture gauge.
Dish garden — an open, shallow arrangement of small plants, usually drier species.
Bottle garden — a terrarium in a narrow-neck bottle; the classic look, but the hardest to build and maintain.
Bioactive — a setup that adds invertebrates such as springtails (which eat mould and decaying matter) or dwarf isopods (which break down leaf litter) as a “cleanup crew.”
Airing out — briefly opening a closed terrarium to let excess humidity escape.

Closed vs Open Terrariums

Type	Best plants	Care rhythm	Beginner notes
Closed tropical	Moss, fittonia, small ferns, peperomia, pilea, selaginella	Low watering, occasional airing, trimming, and mould checks	Best for the classic sealed jar look. Keep out of direct sun so heat does not build inside the glass.
Open tropical	Similar small houseplants, but with more airflow	More frequent watering than closed setups	Easier to adjust if you are nervous about trapped humidity.
Open dry	Haworthia, gasteria, small sedum, dry-tolerant accents	Sparse watering and bright indirect light	Do not seal succulents or cacti in humid jars. Many are better treated as dish gardens.
Bioactive display	Tropical plants plus springtails or isopods	Plant care plus animal/invertebrate welfare	Research species needs first. Do not add animals as decoration.

The one rule that matters more than any other: match every plant to the container’s moisture regime. A fittonia and a haworthia in the same jar will both suffer, because one wants constant humidity and the other wants dry air. Buy small plants, and check each species’ light and moisture needs before mixing them.

Basic Gear

Essential for a first build:

Wide-mouth clear glass container (a clean, intact reused jar works).
Small plants matched to either humid closed conditions or drier open conditions.
Pebbles, LECA, or coarse grit for a drainage layer.
Potting mix matched to the plants (fast-draining mix for open dry setups).
Long tweezers or chopsticks, plus a small spoon.
Spray bottle or small watering bottle.

Optional, but useful:

Activated charcoal (recommended for closed or semi-closed setups).
Moss, stones, bark, driftwood, or other hardscape.
Small brush and cloth for cleaning soil from the glass.
Grow light if you do not have a bright window.

First Session

A concrete first build: a closed tropical terrarium in a wide-mouth jar about 20–30 cm tall.

Plan the scene. Decide where the focal piece (a chunk of bark or a stone) will sit and where the largest plant will go. Sketch it if it helps.
Wash and dry the container. Check for cracks and sharp edges while you are at it.
Drainage layer. Add 2–5 cm of pebbles or LECA.
Charcoal. Add a thin layer (about 1 cm) of activated charcoal over the drainage.
Substrate. Add enough potting mix for the largest plant’s roots to sit securely — usually 5–10 cm in a small jar.
Plant the focal piece first, then smaller plants around it. Use tweezers or a chopstick to make planting holes and firm the mix gently.
Finish with moss, stones, or leaf litter to cover bare soil.
Water lightly until the substrate is evenly damp, not soggy. The goal is damp soil, not standing water in the bottom.
Place in bright indirect light and leave it alone for a week to settle.

Total time is usually 30–60 minutes including cleanup. For an open succulent-style arrangement, use the same steps with a fast-draining mix, water sparingly, and keep the container open with bright indirect light.

First Month

Use the first month to stabilise the terrarium rather than redesigning it constantly. Watch for condensation, yellowing leaves, dry moss, mould, fungus gnats, and plants touching wet glass. A closed terrarium may need airing out if the glass stays heavily fogged all day. An open terrarium may need tiny, targeted watering rather than a full soak.

Care and Troubleshooting

Sign	Likely cause	What to do
Light condensation that clears by midday	Healthy closed water cycle	Do nothing.
Glass fogged all day, standing water at the bottom	Too much water or too much light	Air the container out, stop watering, and check the light level.
Yellow lower leaves	Overwatering or low light	Check substrate moisture before watering again; move to a brighter spot if growth is leggy.
White fuzzy mould on the surface	Wet substrate and poor airflow	Remove the mould and any affected leaves with tweezers, air the container out, and let the surface dry slightly.
Fungus gnats flying around	Constantly wet substrate	Let the surface dry between waterings; a passing wave usually dies out on its own.
Plants touching wet glass	Growth or poor placement	Trim or rearrange so foliage does not sit against damp glass.
Soft, mushy succulent leaves in an open dish	Overwatering	Stop watering, check that drainage is clear, and let the mix dry out.

Diagnose from patterns, not one leaf. Soil moisture, light, and recent changes usually explain more than a single symptom.

Costs

A first closed terrarium can be built for roughly $15–40: a reused or inexpensive wide-mouth jar, two to four small plants (typically $3–8 each), a bag of potting mix, pebbles, and a small bag of activated charcoal. A fuller setup with specialty glassware, prepared kits, rare miniature plants, decorative hardscape, a grow light, springtails, or a workshop can reach $50–150 or more. Prices vary by region and season, and the most common cost sink is replacing plants that were matched to the wrong moisture level.

Space Needed

A small table or kitchen counter is enough for building, and the finished terrarium can fit on a shelf, desk, windowsill, or plant stand. The main requirement is bright indirect light. Direct sun through glass can overheat plants quickly, while dim corners lead to weak growth and rot. A north-facing window or a spot a metre or so from a bright window is usually the sweet spot; a grow light is the fix if you have no suitable window.

Terrarium making works well as a quiet solo hobby, especially for people who like arranging small details. It can also be social through plant swaps, terrarium-building workshops at garden centres and botanical gardens, houseplant groups, and aquarium or vivarium communities. Building a terrarium as a gift is a common social use, since the finished piece is small enough to give away.

Common Mistakes

Sealing succulents or cacti in a humid closed container.
Placing the terrarium in direct sun.
Adding too much water at setup.
Using plants with very different moisture needs in one container.
Building in a narrow-neck bottle before learning the basics.
Watering on a fixed schedule instead of reading the glass or the substrate.
Ignoring mould, yellow leaves, or standing water because the terrarium is supposed to be “self-sustaining.”

Safety / Accessibility

Glass. Containers can be heavy when full and have sharp edges. Carry them with both hands, check reused jars for cracks before buying or using them, and keep them where they cannot be knocked off a shelf.
Soil and charcoal. Use gloves if handling soil, charcoal, sharp rocks, or plants that may irritate skin, and wash hands after building.
Plant toxicity. Most common closed-terrarium plants (moss, fittonia, peperomia, small ferns) are generally regarded as non-toxic to cats and dogs, but check each species with a pet poison control resource or a veterinarian before placing the display where pets or children can reach it. Some open-terrarium succulents, such as aloe, are commonly listed as toxic to cats and dogs if ingested.
Mould and hygiene. Keep the build area and the finished display away from food preparation surfaces, and clean up spilled soil promptly.
Children. The work is well suited to supervised children — the main cautions are glass, small parts, and soil. Wide-mouth containers and pre-mixed substrate make it easier.
Accessibility. The work is seated by nature and sessions are short. Wide-mouth containers, lightweight jars, pre-mixed substrate, and long tools make the hobby manageable for people with limited grip, reach, or mobility.

How We Rate This Hobby

The page ratings treat terrarium making as beginner builds and basic care, not advanced bioactive or exhibition displays.

Rating area	Why it scores this way
Difficulty: 2/5	Building is straightforward; keeping a closed system balanced takes a month or two of observation.
Cost: 2/5	A first build is cheap, especially with a reused jar; specialty glassware, rare plants, and lighting raise costs.
Space: 1/5	A shelf or desk is enough; the real requirement is bright indirect light.
Time: 2/5	A build takes under an hour; ongoing care is a few minutes of observation most days and a trim or watering session weekly to monthly.
Social: 2/5	Mostly a solo craft, with workshops, plant swaps, and vivarium communities as the social layer.

Where It Can Go

Terrarium making can lead toward houseplants, moss propagation, miniature gardening, aquascaping, paludariums, vivariums, botanical styling, photography, plant workshops, or small handmade gifts and decor.

Beginner FAQ

Do terrariums really need no maintenance?

No. A closed terrarium runs a small internal water cycle, so it may need watering only every few weeks, but it still needs the right light, occasional trimming, and attention to mould or struggling plants. “Self-sustaining” means stable, not hands-off.

What is the easiest first terrarium?

A closed tropical terrarium in a wide-mouth jar with moss, fittonia, and a small fern. It is forgiving, teaches you to read condensation, and does not need the precision of a narrow-neck bottle.

Can I use a reused jar?

Yes. A clean, intact wide-mouth jar (pickles, jam, or preserves) works well for a first build. Check for cracks and sharp edges, and make sure the opening is wide enough for your hand or tools.

How do I know when to water?

In a closed terrarium, read the glass: light condensation that clears by midday is healthy, while glass fogged all day with standing water means you should air it out and wait. In an open terrarium, check the substrate and water only when the top layer is approaching dry.

Are terrarium plants safe for pets?

Most common closed-terrarium plants are generally regarded as non-toxic to cats and dogs, but check each species with a pet poison control resource or a veterinarian. Some open-terrarium succulents, such as aloe, are commonly listed as toxic if ingested. When in doubt, keep the display out of reach.

References

Last reviewed: 18 August 2026.

Editorial note: This page gives beginner decision guidance, not species-specific plant diagnosis. Plant needs vary by species, light, and season; check the exact species before mixing plants in one container, and verify pet safety for the exact species you use.

Historical and general references:

PlantExplorers: Dr. Nathaniel Bagshaw Ward — specialist account of Ward’s sealed-jar experiments, the 1833 Sydney shipment, and his 1842 book On the Growth of Plants in Closely Glazed Cases.
Wikipedia: Terrarium — general reference covering the definition, the closed-system water cycle, and related forms such as bottle gardens, paludaria, and vivaria.
Wikipedia: Wardian case — the portable glazed case that made closed terrariums practical.

Practical and safety resources (optional, local):

Your local botanical garden, horticultural society, or gardening centre — terrarium-building workshops are a common beginner class, and staff can advise on plant availability and pet safety in your area.
A pet poison control service or veterinarian — check the exact species before placing a terrarium where pets or children can reach it.

Gardening, bonsai, aquascaping, flower arranging, pottery, model making, dollhouse miniatures, photography, and woodworking all connect naturally with terrarium making.