Open terrarium: succulents and cacti in glass

An open terrarium is a glass bowl, vase or dish with a wide mouth, planted with succulents, cacti or other dry-climate plants in a fast-draining gritty mix. Air moves freely, so humidity stays near room level. It needs the brightest spot you have — at least 6–8 hours of strong light — and water only when the mix is completely dry.

What is an open terrarium?

An open terrarium is an unsealed glass container planted with dry-climate plants. It is the dry counterpart to the Victorian closed Wardian case: because nothing is sealed, water escapes, so you can grow arid-climate plants that would rot in a closed jar. Extension services often call the shallow version a dish garden.

In MOKIZEN's analysis of 591 published layouts, 9 are desert-style, and they most often feature Echeveria and other succulents set against driftwood or petrified wood.

Can succulents really live in a glass terrarium?

Yes, if the container is open and drains well — but not every source likes the idea. RHS and Iowa State say open terraria suit succulents and cacti. South Dakota State Extension does not recommend terrariums for succulents at all, because containers without drainage invite overwatering. The safe reading of both: use a wide, open vessel, ideally with a hole, and water less than you think.

Keep succulents apart from moisture-loving tropicals. No watering routine suits both, so group plants by the same light and water needs.

What soil mix and drainage does an open terrarium need?

Use a sharp-draining mix: a commercial cactus mix, or roughly one part organic material to one or two parts mineral grit such as coarse sand, perlite, pumice or fine gravel. The published ratios differ — SDSU uses 1:1 potting soil to grit, Iowa State about one-third organic to two-thirds mineral, RHS two parts loam-based compost to one part grit — but all three demand fast drainage. If in doubt, go grittier.

Drainage is the real challenge in glass. A pot with a hole is best. Without one, University of Vermont Extension adds a gravel base and a little activated charcoal under the mix, while Iowa State warns that a gravel layer is no substitute for a hole. Use the gravel layer, but water in small, measured amounts so nothing pools at the bottom.

Keep the container modest and shallow: a large volume of mix stays wet for too long, and smaller, shallower dishes dry out faster, which succulents like.

How do you plant an open terrarium step by step?

Planting takes an afternoon: layers first, biggest plants next, top dressing last.

1. Choose a wide-mouthed container, ideally with a drainage hole, and clean it.
2. If there is no hole, add a gravel or pebble base and a thin layer of activated charcoal.
3. Add a few centimetres of gritty cactus mix.
4. Plant the largest pieces first, keep plants with similar needs together and leave space between them.
5. Top-dress with sand or fine gravel — it keeps the plant necks dry — then add stones and wood, leaving air at the soil surface.
6. Water lightly and let the mix dry fully before the next watering.
7. Place it in the brightest position you have and rotate it now and then.

How much light does a succulent terrarium need?

Give it the brightest spot available: most succulents need at least 6–8 hours of strong light a day. Iowa State asks for 10 hours or more of bright light, SDSU puts the minimum at 6–8 hours in a south or west window, and RHS simply says a sunny windowsill all year. Aim high; in weak light the plants stretch, pale and weaken, a problem called etiolation. A grow light fills the gap, and turning the container stops plants leaning.

Glass magnifies and holds heat. RHS notes that direct sun is fine for cacti, but watch for scorching behind a hot window — and never put a closed jar in the sun.

How often do you water an open terrarium?

Water by the soak-and-dry rule: water thoroughly, then not again until the mix is completely dry to the touch. Intervals vary — Iowa State says every 2–3 weeks, SDSU once a week or less — so let the finger test decide rather than the calendar. In a glass without holes, give a small measured amount instead of a soak.

Why are my terrarium succulents rotting, and what are common mistakes?

Rot is almost always overwatering, the most common cause of succulent death: water sits in the sealed glass base and the roots die, showing as soft, yellowing, mushy stems.

• Overwatering: use soak-and-dry, a gritty mix, a hole where possible and small measured amounts in glass.
• A lid or a narrow-necked jar: humidity builds up and the plants rot. Use open, wide-mouthed containers.
• Too little light: stretched, pale, weak plants. Move to the brightest window or add a grow light.
• Mixing succulents with moisture lovers: group plants by need.
• An oversized container or deep soil: the mix stays wet too long. Go modest and shallow.

Does an open terrarium need springtails or isopods?

Usually not. Springtails and isopods need damp conditions, so they belong in closed and tropical builds. In a dry desert-style bioactive enclosure, the cleanup role goes to dry-tolerant beetles instead; a small succulent dish normally runs with no animals at all.

이 가이드의 식물과 생물

• Zebra Haworthia (Haworthiopsis attenuata (syn. Haworthia attenuata))

3D로 보기

• 사막 기하학 다육식물

관련 가이드

• Closed terrarium: how to build one that lasts
• Wabi-kusa: how to make and grow an emersed plant ball

출처

1. Terrariums and bottle gardens — Royal Horticultural Society
2. How to grow cacti and succulents — Royal Horticultural Society
3. Growing succulents indoors — Iowa State University Extension (Yard and Garden)
4. How to care for succulents indoors — South Dakota State University Extension
5. Building a dish garden — University of Vermont Extension
6. How to create and care for a terrarium — Iowa State University Extension (Yard and Garden)
7. Terrarium — Wikipedia
8. Bioactive terrarium — Wikipedia
9. Aquascape insights (591 published layouts) — MOKIZEN

이 출처들을 바탕으로 작성; 최종 업데이트 2026-09-23.

리빙 월드 둘러보기 · 수초·생물 관리 가이드 · 아쿠아스케이핑 가이드 · 591개 실제 수초 어항 분석 데이터 · 3D 에디터 열기