

Star Moss, Hairy Screw Moss
Tortula ruralis
Tortula ruralis gets its common name “Star Moss” for its unique bundles of star shaped leaves that wrap around the stems. Its second name of “Screw Moss” comes from the fact that the leaves become twisted when dry (Tortula” is latin for twist). It’s a short moss by all means, but it comes with lots of character and a hardy disposition. Star Moss can handle a wide variety of environmental conditions and can be found in extreme climates across the world. Honestly, it’s about as bulletproof as mosses get.
At a Glance
- Moss
- Medium - high indirect light
- 55-80°F (12-26°C)
- Infrequent, even moisture
- 0.5-2 inches
- Low - high humidity (20-80%)
Where to Buy Star Moss (These Links Are For Polytrichum formosum, a Different Star Moss)
See the links below to purchase from reputable terrarium plant shops and marketplaces (may include affiliate links).
Terrarium Plant Guide
Tortula ruralis Care & Growth
Lighting
Star Moss can handle way more sunlight than most other terrarium plants, but will happily grow in a typical low-light environment too.
Watering
Star Moss is unlike most other terrarium mosses in that it is highly drought tolerant. It’ll naturally grow in arid conditions. Its colour and shape are both great indicators of how much moisture it’s holding – green and ‘star-like’ when wet, and red and twisted when dry.
Substrate
Tortula ruralis is found in a huge range of environments across the world; from arctic to desert. It’s safe to say, your substrate of choice is probably going to be fine.
Temperature & Humidity
Star Moss is a hardy plant, and it’ll handle a range of temperatures and humidities. It’ll do fine in your typical tropical terrarium, and a high humility will provide more than enough moisture for it to thrive.
Growth
Tortula ruralis is a slow growing moss and it doesn’t grow particularly tall, which makes it a great choice for terrariums.
Propagation
To propagate Star Moss, simply divide into smaller patches and place in separate areas of the terrarium. Don’t expect quick results though.
Varieties & Similar Plants
Star Mosses come in a variety of forms. Polytrichum formosum being the most commonly available (via the links above) which is a larger variety, with spiky leaves up the length of the stem.
Common Problems
Honestly, Star Moss is one of the easiest plants to grow in a terrarium. You shouldn’t have any problems in growing this. However it can go dormant if less without moisture for long periods, so this could be mistaken for it struggling or dying.

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