Racomitrium japonicum

Sunagoke Moss, Japanese Rock Moss, Sand Moss

Easy careTerrestrialNon-toxic2–5 cm

A hardy, drought-tolerant moss widely used for green roofs in Japan. It forms dense, dull green to yellowish-green mats of irregularly branched stems (2–5 cm tall) with papillose leaves that curl inward when dry. Papillose means the leaf surface is covered in tiny bumps, which help trap moisture from the air. Tolerant of heat, drought, and low nutrients, it is one of the few mosses suited to open terrariums and drier setups where good air circulation matters. Now reclassified as Niphotrichum japonicum.

Build a terrarium with this plant

Care

Prefers medium humidity, bright indirect light, with -5–25 °C, and reaches 5 cm at maturity.

Light

Bright indirect(preferred)Indirect light

Humidity

Medium (40–60%)(preferred)High (60–80%)Low (30–40%)

Temperature

-10°C15°C40°C
-5°C – 25°C

Soil

Sandy(preferred)RockyWell draining

Moisture

Dry(preferred)Moist

Soil pH

5 – 7

Propagation

Separate clumps and press onto well-drained sandy substrate. Keep lightly moist with good air circulation until established. This is the most practical method.

Native range

Native to China and Eastern Asia.

Appearance

Growth habit

ClumpingCreeping

Leaf shape

Lance

Leaf texture

Rough

Frequently asked

Can Sunagoke Moss grow in a closed terrarium?

Sunagoke Moss prefers medium (40–60%) humidity, which is below the level a closed terrarium typically maintains. It is better suited to an open terrarium or houseplant setup.

Does Sunagoke Moss need drainage?

Yes. Sunagoke Moss prefers a dry-leaning substrate and benefits from a drainage layer to prevent root rot.

What humidity does Sunagoke Moss need?

Sunagoke Moss does best in medium (40–60%) humidity.

Is Sunagoke Moss pet-safe?

Sunagoke Moss is considered non-toxic to common household pets.

How tall does Sunagoke Moss grow?

Sunagoke Moss typically reaches 2–5 cm at maturity.

How do you propagate Sunagoke Moss?

Sunagoke Moss can be propagated by division or spores.

References

  1. 1

    GBIF — Niphotrichum japonicum (Dozy & Molk.) Bedn.-Ochyra & Ochyra

    https://www.gbif.org/species/8405115
  2. 2

    World Flora Online — Racomitrium japonicum Dozy & Molk.

    https://www.worldfloraonline.org/taxon/wfo-0001172105
  3. 3

    Frontiers in Microbiology — Sunagoke Moss for Green Roof Applications

    https://pmc.ncbi.nlm.nih.gov/articles/PMC6403164/
  4. 4

    PictureThis — Racomitrium japonicum Care Guide

    https://www.picturethisai.com/care/Racomitrium_japonicum.html
  5. 5