Moss Campion (Cushion Pink) care

Light

Moss Campion needs sun on the leaves, not just bright ambient room light. Full sun for the entire day is essential. The tight cushion form and prolific flowering depend on maximum light. Any shading causes open, untidy growth and severe reduction in bloom. Position on an open south-facing aspect. A south or west-facing windowsill in the northern hemisphere is the default; anywhere else, expect the plant to stretch and pale out within a season.

Watering

Water moss campion sparingly in summer; almost none in winter. The actual day count varies with pot size, light, and season — the finger test (or lifting the pot to feel its weight) is more reliable than a fixed calendar. Empty any drainage saucer afterwards so the pot isn't sitting in water. Water very lightly in the growing season, allowing the cushion to nearly dry between waterings. Excess moisture trapped in the cushion causes rapid rot. In wet winter climates, overhead glass or polythene protection is strongly recommended.

Soil and pot

Moss Campion grows best in sharply drained, gritty, mineral, neutral to slightly alkaline. Best in a mix of limestone chippings and lean loam. pH 6.5–8.0. In nature grows in rock crevices with deep, cool root runs. In cultivation, use a trough or raised bed with at least 15 cm of grit below the cushion. Never use peat-based or water-retentive compost. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Moss Campion sits happiest at around Low (20–45% RH) humidity and -35°C to 18°C (-31°F to 64°F). Originates in dry, cold, high-altitude and arctic environments. High ambient humidity combined with warmth is very damaging. Grow in open, well-ventilated positions or in an alpine house in wetter climates. If you keep the room above year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed moss campion sparingly. No feeding needed; rich soils are harmful. At most, top-dress with a thin layer of grit and a few granite or limestone chips annually to maintain drainage around the cushion collar. Any fertiliser application risks destroying the compact habit. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on moss campion in the Growli community. Each is annotated with the most common cause so you know where to start.

• Cushion rot (Botrytis / Phytophthora) — The primary cause of death in cultivation. Excessive moisture in the cushion, especially in warm wet winters, triggers fungal or oomycete rot. Ensure absolutely perfect drainage and protect from overhead rain in winter with a sheet of glass or perspex.
• Very slow establishment / failure to thrive — Moss Campion grows just a few millimetres per year; it can take 5–10 years to form a flowering-sized cushion. Poor drainage or heat stress will set it back or kill it. In lowland gardens, the alpine house is most reliable.
• Aphids on flower stems — Spring flower stalks can attract aphids. Remove manually or spot-treat with insecticidal soap. Avoid systemic pesticides that may damage the slow-growing cushion tissue.

Propagation

Extremely challenging. Small cushion pieces can be carefully detached with a scalpel in late summer, rooted in near-pure grit with minimal moisture. Seed needs cold stratification (8–12 weeks at 2–4°C) and surface sowing on gritty compost; germination is erratic. Commercial plants are usually from seed. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Moss Campion is pet-safe. Silene acaulis (family Caryophyllaceae) is not individually listed by ASPCA. The genus Silene and family Caryophyllaceae are not associated with any documented toxic principles in cats, dogs, or horses in veterinary literature. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Moss Campion deep-dive guides

Every aspect of moss campion care, each with its own calibrated guide:

• Common moss campion problems & fixes
• Moss Campion watering schedule
• Moss Campion light requirements
• Best soil mix for moss campion
• Moss Campion fertilizing guide
• When to repot moss campion
• How to propagate moss campion
• How to prune moss campion
• What's eating my moss campion?
• Moss Campion growth rate & size
• Moss Campion cold hardiness
• Moss Campion temperature & humidity
• Is moss campion toxic to cats & dogs?
• Is moss campion toxic to cats?
• Is moss campion toxic to dogs?
• Getting moss campion to bloom

Featured in these plant shortlists

Moss Campion qualifies for 7 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best pet-safe houseplants — Houseplants the ASPCA lists as non-toxic to cats and dogs — every one verified against the ASPCA toxic and non-toxic plant list.
• Best flowering houseplants — Indoor plants grown for their blooms — selected from the flowering species in Growli’s plant-care library.
• Best pet-safe flowering plants — Flowering houseplants the ASPCA lists as non-toxic to cats and dogs — colour and blooms in a pet home, without the worry.
• Best pet-safe plants for bright light — Non-toxic to cats and dogs and happy in a bright, sunny spot — safe plants for your best-lit windowsill.
• Best houseplants for full sun — Houseplants that want direct sun — the species for a hot south or west-facing windowsill where shade-lovers scorch.
• Best cat-safe plants — Houseplants the ASPCA lists as non-toxic to cats (and dogs) — safe greenery for a home with a curious cat.
• Best dog-safe plants — Houseplants the ASPCA lists as non-toxic to dogs (and cats) — safe greenery for a home with a curious dog.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Moss Campion is also known as Moss Campion, Cushion Pink, and Moss Pink.

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