---
title: Fire moss in a terrarium | Glass Jar Garden
description: Fire moss (Ceratodon purpureus): A low turf with red stalks, happiest on bright, dry soil. Needs light 3,000 to 50,000 lux, humidity 30 to 80 % RH,...
url: https://glassjar.garden/guide/moss/ceratodon-purpureus/
---

Moss

# Fire moss
Ceratodon purpureus

Easy · Open jar only

A low turf with red stalks, happiest on bright, dry soil.

## What the simulation uses

- Light: 3,000 to 50,000 lux (The brightness it grows well in.)

- Humidity: 30 to 80 % RH (Air moisture it is happy in; below the lower end it dries out.)

- Temperature: 5 to 30 °C (Comfortable range; outside it growth slows.)

- Dies at: below -30 or above 48 °C (Days beyond these temperatures kill it.)

- Soil pH: 5 to 6.5 pH (Soil acidity it prefers.)

- Grows up: 0.04 cm/month (How fast it gains height in good conditions.)

- Spreads: 0.06 cm/month (How fast its edge creeps outwards.)

- Thickens: 1.75 %/month (How fast its cover fills in on its own ground.)

- Copes with wet: fair (How well it stands soggy soil; poor means rot comes quickly.)

- Copes with still air: fair (Sealed jars have still air; poor means grey mould finds it.)

- Copes with shade: fair (How well it holds on in dim light.)

- Copes with drying: excellent (How well it survives the jar drying out.)

- Water use: 0.035 ml/cm²/day (Water that evaporates off the cushion each day in room air.)

- Holds water: 0.25 ml/cm² (Water a cm² of moss soaks up and keeps.)

- Grows on: soil, stone (Where it can take hold and spread. Moss that cannot grow on stone thins out there.)

## Care

- Day length: 10 to 14 h

- Substrate: Dry

## What kills it

- constant wet in still air
- deep shade

## Description
One of the first mosses to settle on bare, disturbed ground, it grows slowly, around half a centimetre a year. It copes with some shade but not deep darkness. Use an open jar, because constant wet in still air does it in.

Also called redshank, purple horn-toothed moss.

Estimated, where sources were thin: temp_c; humidity_rh_pct.

## Sources

- [en.wikipedia.org/wiki/Ceratodon_purpureus](https://en.wikipedia.org/wiki/Ceratodon_purpureus)
- [ohiomosslichen.org/moss-ceratodon-purpureus](https://www.ohiomosslichen.org/moss-ceratodon-purpureus/)
- [nora.nerc.ac.uk/id/eprint/1131/1/BRYOATT.pdf](https://nora.nerc.ac.uk/id/eprint/1131/1/BRYOATT.pdf)

[Grow it in a jar](https://glassjar.garden/?guide=moss/ceratodon-purpureus)

[Fern moss](https://glassjar.garden/guide/moss/thuidium-delicatulum/) · [Flame moss](https://glassjar.garden/guide/moss/taxiphyllum-flame/) · [All moss](https://glassjar.garden/guide/moss/)