Moss terrariums: types of moss, where to get it responsibly and how to keep it green
TUREFF• •0
Moss is the quiet backbone of most closed terrariums. It covers bare soil, holds moisture evenly, looks good on its own and needs very little. A jar with nothing but moss, stones and a piece of wood can be one of the easiest terrariums to keep alive. It does, however, have its own needs, and where the moss comes from matters more than many people realise.
How moss is different
Mosses have no true roots. They anchor themselves with fine threads and take in water mostly through their leaves rather than from the soil below. That is why moss in a terrarium cares more about humidity and moisture on its surface than about deep, rich compost. It also means moss dries out fast in open air and greens up quickly when it gets wet again.
Common kinds used in terrariums
Moss is sold by growth form more often than by species, and the common names vary between sellers. The main types you will meet:
- Cushion or pillow moss: grows in rounded mounds. Good for hills and texture.
- Sheet or carpet moss: forms a flat, spreading mat. Good for covering the ground in one piece.
- Mood moss and other upright clumping mosses: taller tufts with a slightly windswept look.
- Fern-like mosses: delicate, feathery fronds that spread along the surface.
- Rock and wood mosses: grow naturally on stone and bark, and can be pressed onto hardscape.
Mosses from shady woodland floors tend to do better in closed jars than those from exposed, sunny walls and roofs, which are adapted to drying out and can struggle in constant humidity.
Sourcing responsibly
It is tempting to lift a patch of moss on a walk, but please do not take moss from the wild.
- It is often against the law. In Great Britain, the Wildlife and Countryside Act 1981 makes it an offence to uproot any wild plant without the permission of the landowner or occupier, and mosses count as plants for that purpose. Separately, taking plants from land for commercial purposes without permission can fall under theft law. Protected sites such as Sites of Special Scientific Interest have stricter rules again, and some rare mosses are protected outright. Rules elsewhere differ; check the law where you live.
- It is slow to come back. Moss mats can take many years to grow, and they shelter insects and other small creatures.
- It can bring in pests. Wild moss can carry slugs, mites, eggs and moulds into a sealed jar.
Better options:
- Buy moss from sellers who grow it or harvest it with permission, and ask them where it comes from.
- Ask friends whose own garden paths, patios or pots grow moss, with their permission, and take small pieces.
- Grow your own: crumble a small piece over damp substrate in a covered tray and keep it humid. It is slow, but it works.
If you do take moss from your own garden, rinse it, pick it over and consider keeping it in a separate container for a week or two before it goes into a finished jar.
Planting moss
- Lightly moisten the substrate and the moss.
- Press the moss firmly onto the surface so its underside is in contact. Gaps underneath dry out.
- Pin small pieces onto steep slopes with a toothpick until they attach.
- Mist and close the jar.
Care
- Light: bright indirect or fairly low light. Direct sun through glass will scorch it. Moss under a weak LED light can do very well.
- Water: keep it damp. A light mist when the moss looks paler or the jar has had no condensation for a while. Rainwater, filtered or distilled water helps if your tap water is very hard and leaves white marks.
- Air: an occasional airing helps prevent mould in very wet jars.
- Brown patches: usually too dry, too hot or too much direct sun. Patchy browning can also be natural ageing; trim it out and the rest often fills in.
- Yellowing or stretching: usually too little light.
Ask about a moss that has gone brown, or share how you sourced and grew yours, in the comments below.