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How to plant a terrarium: layers, then a light mist

Updated: 21 October 2026

The glass is on the table, the plants are still in their nursery pots, and the leaflet may not be in English. How to plant a terrarium is the order of the layers, then a light first watering, then a lid only if the plant wants humidity. The [terrarium comparison](/hub/houseplants/terrarium) is where the three listings sit. This page is the sequence for the PYEF jar, which includes the layers and not the plant, and for the Homtone case, which includes neither. Peter F. set that sequence on 21 October 2026. This is not a lab test. A qualifying purchase can earn a commission at no extra cost to you.

The glass is on the table, the plants are still in their nursery pots, and the leaflet may not be in English.

Our top picks

Clementoni Clementoni Harry Potter kit, 7+

Best overall

Clementoni Clementoni Harry Potter kit, 7+
5.5/10about £12.90
View offer
PYEF CRAFTS PYEF CRAFTS 1 litre jar kit

Rank 2

PYEF CRAFTS PYEF CRAFTS 1 litre jar kit
7.4/10about £24.99
View offer
Homtone Homtone golden birdcage, 18 cm

Alternative

Homtone Homtone golden birdcage, 18 cm
6.1/10about £32.95
View offer
On this page
  1. 1.Closed jar layers
  2. 2.Open case or geometric door
  3. 3.First water and the lid
  4. 4.What the kit does not decide

Closed jar layers

Start with clean, dry glass. Kew’s order is pebbles, a scatter of charcoal, then soil deep enough for the roots, with leaves clear of the glass. BBC Gardeners' World uses about 2 cm of gravel, a spoon of charcoal, and about 6 cm of moist compost on a closed build. The Royal Horticultural Society uses gravel, then peat-free compost and grit at about four parts to one. Those are publisher steps, not one UK measurement. In the PYEF 1 litre jar, keep the soil thin. Use one small Fittonia or fern, and break dried blocks before you pour. Which plant suits a lid is on closed or open terrarium.

Open case or geometric door

BBC Gardeners' World’s open stack is grit, then about 4–5 cm of cactus compost, then succulents, a pale gravel top, and spare water. Do not copy that depth into a corked litre. The Homtone birdcage, 18 × 18 × 23 cm, arrives empty. UK reviews say the door will not pass a nursery pot. Ease a bare-root succulent or a plug through the opening. Do not force a 9 cm pot. Reviews split on leaks if you water freely. A fern is the wrong humidity for this case.
Clementoni Clementoni Harry Potter kit, 7+

Testsieger

Clementoni Clementoni Harry Potter kit, 7+
5.5/10about £12.90
View offer

First water and the lid

On day one, mist rather than soak. The Royal Horticultural Society suggests a mister down the glass, then a look after a couple of days. Kew treats a fogged pane as too much water. BBC Gardeners' World uses fog on up to one third of the jar, and almost none as a sign to add about a tablespoon. One RHS project soaks the drainage layer. Do not blend those into one dose. These listings state no millilitres. Cork only a humid plant. Leave the Homtone flap open for succulents. Hard fog or white fuzz belongs on terrarium mould.

What the kit does not decide

The PYEF box does not choose the plant, and one review found no English on the sheet. Dried blocks are what some buyers received. The Homtone box has no stones, charcoal or compost. Bamboo tongs fit a narrow neck. They do not widen the Homtone door. The Clementoni set is seeds and plaster for ages 7–16, not this layer order. If you have not paid yet, use the terrarium buying guide. A smashed pane is for the amazon.co.uk seller. Which? says the retailer answers for damage in transit.

Common questions

What goes in first, charcoal or stones?
Stones or gravel go in first, then a little charcoal, then soil. Kew uses 2–3 cm of pebbles and a scatter of charcoal. BBC Gardeners' World uses about 2 cm of gravel and a spoon of charcoal on a closed build. The Royal Horticultural Society starts with gravel as well. Charcoal on the bare glass, with no drainage under it, is the reverse of those three sequences.
How deep should the soil be in a 1 litre jar?
Keep it shallow enough for one small plant. BBC Gardeners' World’s closed figure is about 6 cm of compost after a thin gravel layer, which is already a lot of a 20 cm PYEF jar once you add stones. Kew only says deep enough for the roots, with room to grow. Do not copy the open-build 4–5 cm of cactus compost into a corked litre and then add a fern on top.
How much water on day one?
Mist the glass. Do not pour until water sits in the stones, unless you are following the heavier RHS project method and you accept that it disagrees with the mister advice. Check the pane after a couple of days. Fog across the glass means you added too much, on Kew’s reading. There is no millilitre figure on these listings.
Can I use the bamboo tools in the PYEF kit for a narrow neck?
Yes. The kit includes two shovels, a rake and bamboo tongs, and a bullet also names a bamboo spoon. They are meant for a jar you cannot fit a hand into. They do not help you pass a nursery pot through the Homtone door, which UK reviews already call too small.
What if the Homtone door will not take the pot?
Unpot the plant and pass a small bare-root succulent or a plug through the flap. If the root ball will not go, do not force the hinge. That case is 18 × 18 × 23 cm and still a small planting. Skip it and use an open pot you can plant from above when the door is the limit.
Should the plants be wet before they go in?
Knock excess water off the nursery root ball before it goes into a closed jar. A dripping plug on top of moist compost is how the first fog starts. Succulents for the open case should not be soaked either. BBC’s open build says water sparingly after the grit and cactus compost are in place.
When do I put the lid on?
Put a cork on after the plant is in, the leaves are clear of the glass, and you have misted rather than flooded. Only a humid plant gets that lid. Leave a succulent case open. If the closed glass is already opaque with water, vent it before you treat the lid as finished. White growth after that is a different job from planting.

Related pages

Best terrarium

Terrarium

Terrarium buying guide: plants, litres, door, glass

Closed or open terrarium: match the plant to the lid

Terrarium mould: fog, white fuzz, and when to empty

Sources

Public UK sources named below. amazon.co.uk prices, stars and review counts on these three listings were read for this comparison. Page updated 21 October 2026. Other price bands are a 20 October 2026 snapshot, not a market average.

  1. RHS, Terrariums and bottle gardens (retrieved 21.10.2026)
  2. Kew, Make your own terrarium (retrieved 21.10.2026)
  3. BBC Gardeners' World, How to make a terrarium (retrieved 21.10.2026)
  4. BBC Gardeners' World, Terrarium care (retrieved 21.10.2026)
  5. Consumer Rights Act 2015, goods rights (retrieved 21.10.2026)
  6. Which?, damaged goods in the post (retrieved 21.10.2026)
  7. GOV.UK, General Product Safety Regulations 2005 (retrieved 21.10.2026)
  8. GOV.UK, invasive non-native plants (retrieved 21.10.2026)
  9. terrarium.co.uk, why a terrarium goes mouldy (retrieved 21.10.2026)
  10. Small & Green, terrarium care (retrieved 21.10.2026)