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.

Where to Buy Star Moss
See the links below to purchase from reputable terrarium plant shops and marketplaces (may include affiliate links). Currently, these links are for Polytrichum formosum, a different Star Moss as I cannot for the life of me find any Tortula ruralis.
Tortula ruralis Care & Growth
Plant Type | Moss |
Lighting | Medium – high indirect light |
Temperature | 55-80°F (12-26°C) |
Watering | Infrequent, even moisture |
Humidity | Low – high humidity (20-80%) |
Growth | 0.5-2 inches |
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.
If you’re finding it hard to get your hands on Star Moss, check out our full Terrarium Moss Guide for more inspiration!
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.