Moss campion Silene acaulis
Moss campion (Silene acaulis) is an evergreen perennial groundcover in the Caryophyllaceae family, native to Arctic and high mountains of Europe, Asia and North America. It grows 2–6 cm (1–2 in) tall and 20–40 cm (8–16 in) wide, wants full sun and moderate water, and is hardy to about -45 °C (-49 °F). Space plants about 20 cm (8 in) apart.
Plan Moss campion in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Moss campion at a glance
| Type | Perennial groundcover, evergreen |
|---|---|
| Family | Caryophyllaceae |
| Mature height | 2–6 cm (1–2 in) |
| Mature spread | 20–40 cm (8–16 in) |
| Spacing | 20 cm (8 in) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Moderate; drought tolerance low, waterlogging tolerance none |
| Soil pH | 5.5–8 |
| Cold hardiness | About -45 °C (-49 °F) once established (roughly USDA zone 2) |
| Heat stress | Likely above about 22 °C (72 °F) |
| Flowering | from about June for 3–5 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | High |
| Pollinator value | Moderate |
| Edible | Not grown as food |
| Native to | Arctic and high mountains of Europe, Asia and North America |
| Common in gardens of | 🇬🇧 United Kingdom, 🇳🇴 Norway, 🇷🇺 Russia |
Is Moss campion toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
No toxicity reported in ASPCA or standard poison references.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Moss campion
No well-documented helpful pairing. Group it with plants that like full sun and moderate water.
See Moss campion in a botanical garden
It grows in these sample gardens, which you can walk through in 3D:
- Arctic-Alpine Botanic Garden (20 plants)
- Jardin botanique de Montréal (20 plants)
- Kew: glasshouses and rock garden (9 plants)
Questions about Moss campion
- How far apart should I plant Moss campion?
- About 20 cm (8 in) apart, centre to centre. A mature plant spreads 20–40 cm (8–16 in).
- Does Moss campion need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Moss campion need?
- Moderate water. Drought tolerance is low and waterlogging tolerance none.
- How cold-hardy is Moss campion?
- It tolerates about -45 °C (-49 °F) once established, roughly USDA zone 2.
- When does Moss campion flower?
- From about June for 3–5 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Moss campion poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. No toxicity reported in ASPCA or standard poison references.
- What grows well with Moss campion?
- There is no well-documented companion pairing for Moss campion. Group it with plants that like the same sun (full sun) and water (moderate).
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- RHS Plant Finder, Royal Horticultural Society
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- Wildflowers and meadows, Plantlife (UK)
Notes and assumptions
- Alpine: needs sharp drainage (scree, gravel or a rock-garden pocket) and resents winter wet more than cold.
- A dense cushion plant that grows very slowly (cushions may be centuries old); dislikes hot, humid lowland summers.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Sweet William Dianthus barbatus
- Carnation Dianthus caryophyllus
- China pink Dianthus chinensis
- Snow-in-summer Cerastium tomentosum
- Soapwort (bouncing bet) Saponaria officinalis
- Rock soapwort Saponaria ocymoides
- Creeping baby’s breath Gypsophila repens
- Maiden pink Dianthus deltoides