Almost any moss survives in a closed terrarium, but some look far better and behave far better than others. A quick guide to choosing.
Cushion or carpet
Cushion mosses grow in domed mounds and hold their shape beautifully behind glass, giving a terrarium structure and little hills. Carpet or feather mosses spread flat to cover ground and soften the floor between features. Most good terrariums use one or two cushions for height and a carpet to knit it together.
Reliable choices
- Bun moss (Leucobryum): the classic pale-green dome, holds its shape for years.
- Broom fork-moss (Dicranum scoparium): springy combed cushions, very photogenic.
- Mood moss (Dicranum types sold under this name): larger clumps for a wilder look.
- Sheet or carpet moss (Hypnum and relatives): the flat green floor.
- Fern moss (Thuidium): fine, frond-like, lovely as an accent.
Where to get it
You can collect small amounts from your own garden, walls and paths, which is free and local; take a little from several places rather than stripping one patch, and rinse off soil and creatures. Specialist terrarium suppliers sell named, clean cushions if you want a particular look or to avoid introducing pests.
What to avoid
Skip bog moss (sphagnum) unless you are deliberately running a wet, boggy setup, as it wants saturation. Be wary of moss lifted with a lot of soil and leaf litter, which brings in mould spores, slugs and springtails; a closed jar will happily incubate all of them. A quick rinse and a look-over saves trouble later. See the terrarium guide for building and care.