How to Grow Peacock Fern
Selaginella uncinata
Peacock fern is a low, creeping spikemoss grown for its iridescent blue-green foliage, not a true fern and never in flower. Give it shade or bright indirect light with no direct sun, which bleaches the blue sheen. Keep the compost constantly moist but never waterlogged, and keep the air humid; a terrarium, bottle garden or steamy bathroom is ideal. Feed lightly once a month in spring and summer and trim any crispy brown stems. It is hardy outdoors to about USDA zone 6 as a groundcover for moist shade.
In your Leaftide garden 
- Height
- 15 cm
- Spread
- 45 cm
- Light
- Bright indirect light
- Water
- High
- Feed
- Light monthly feed in spring and summer
- Prune
- Trim brown or straggly stems
Yearly Lifecycle
Care Essentials
Feed once a month from spring to late summer with a balanced liquid fertiliser at quarter to half strength. Do not feed in autumn and winter; strong feed scorches the fine foliage.
Watch For
- Crispy brown stems from dry air
- Root and stem rot in waterlogged compost
- Faded colour in too much direct sun
- Spider mites in warm, dry rooms
- Fungus gnats in constantly wet compost
Pet Safety
Care Requirements
Light
Shade to bright indirect light, no direct sun
Grow in bright indirect light or shade; a north or east window, or a few metres back from a brighter one, is ideal. Direct sun scorches the stems and fades the blue sheen to green.
Watering
Keep constantly moist, never dry, never waterlogged
Water as soon as the surface starts to lose its dampness; the compost should never dry out. Use rainwater or filtered water if your tap water is hard, and never leave the pot standing in water.
Humidity
High humidity, 60% or more
Dry indoor air turns the stems brown and crispy. A terrarium, bottle garden, cloche or humid bathroom is the most reliable way to keep it lush.
Fertilizing
Light monthly feed in spring and summer
Feed monthly from spring to late summer with a balanced liquid fertiliser at quarter to half strength. Skip feeding in autumn and winter and in closed terrariums.
Pruning
Trim brown or straggly stems
Snip off brown, crispy or overlong stems to keep the mat dense. Outdoors, cut winter-damaged growth back to the ground in early spring before new blue growth appears.
Spacing
25-35 cm apart as a groundcover
A single plant spreads to about 45 cm across. Outdoors, plant 25-35 cm apart in moist, humus-rich shade and the creeping stems will knit together within a season or two.
Support
No support needed
A low, creeping plant that roots as it spreads, so it needs no staking or training. In hanging pots the stems trail gently over the edge.
Growing Tips
Shade brings out the blue
The metallic blue sheen is strongest in shade or soft indirect light. Direct sun fades the colour to plain green and scorches the stems.
Never let it dry out
Spikemosses have no way to store water. A single dry spell turns the stems brown and crispy, so check the compost every few days.
Humidity is the secret
Aim for 60% humidity or more. A terrarium, bottle garden, cloche or bathroom keeps it lush far more reliably than misting.
Easy to propagate
Stems root wherever they touch moist compost. Pin a stem down or lay cut pieces on damp compost under cover and they root in a few weeks.
Pests & Diseases
Pest Spider Mite
Identification: Tiny sap-sucking mites that cause pale speckling and fine webbing between the stems, mostly in warm, dry rooms.
- Raise the humidity; spider mites dislike moist air.
- Rinse the plant gently and treat with insecticidal soap, repeating weekly.
Pest Fungus Gnat
Identification: Small dark flies hovering over the compost; their larvae feed on organic matter and fine roots in constantly wet compost.
- Use yellow sticky traps to catch the adults.
- Water with a Bacillus thuringiensis israelensis (BTi) product or use beneficial nematodes against the larvae.
Disease Root and Stem Rot
Symptoms: Stems go dark, soft and collapse at the base, starting in the centre of the mat. Caused by compost that stays waterlogged or a pot without drainage.
Treatment: Cut away the rotten stems, root healthy pieces in fresh compost and water less heavily.
Prevention: Keep the compost moist rather than soggy, use a free-draining mix and never leave the pot standing in water. In closed terrariums, add a drainage layer.