Christmas fern

Polystichum acrostichoides

In other languages: Polystichum (Nederlands) · Polystichum (Français)

Polystichum acrostichoides, known as Christmas fern, comes from the deciduous woodlands of eastern North America. It is a sturdy, evergreen fern with glossy, dark green, leathery fronds 30–60 cm long. The leaflets have a small ear at the base, like a Christmas stocking. The fronds stay green even after frost and lie flat on the ground in winter. It is very hardy, easy and grows well in part shade, on a shady slope or under trees. A dependable plant for any shade garden.

Updated on 9 October 2026

Light
Partial shade or shade
tolerates little sun
Moisture
Normal
no wet feet
Legal basis
Sand, loam or clay
acid to neutral
Hardiness
Fully hardy
down to -30 °C
Size
0.5 m
tall, 0.6 m wide

Key facts
Pruning months	March
Height	0.5 m
Native to Belgium	No, planted
Poisonous to people and pets	Not known to be poisonous

Identify

Christmas fern: how do you recognise it?

Habit: Sturdy, funnel-shaped clump 50 cm tall and 60 cm wide, slow-growing.
Fronds: Leathery, glossy dark green, once-pinnate; the leaflets have a small ear at the base. Stays green in winter.
Spores: Ferns do not flower; the fertile leaflets at the top are smaller and carry spores on the underside.
New fronds: In spring the fronds unroll like a crozier, covered in silvery scales.
Roots: A sturdy rhizome with fibrous roots; the plant spreads slowly.

Plants: March–May and September–October · Pruning: March

In your garden

Why grow it?

Evergreen: the glossy fronds stay attractive until spring, even under snow.
Very hardy, down to about −30 °C, and not fussy.
A well-behaved clump that does not run, ideal for a shady slope or under trees.
Gives structure and greenery in winter, when few other shade plants still look good.
Little work: no pruning, no feeding, hardly any diseases.

Christmas fern: where does it grow best?

Part shade to shade; in full sun the fronds turn yellow or scorch.
Humus-rich, free-draining soil: sand, loam or chalky soil, acid to neutral; once established it also tolerates some drought.
A shady slope, the foot of a wall or under trees.
Allow 50–60 cm of space per plant.

Light: Partial shade and shade
Soil type: Sand, loam or clay
Acidity: Acid or neutral
Moisture: Normal
Size: 0.5 m tall, 0.6 m wide
Hardiness: Hardy (to -30 °C)

Goes well with

Hosta: Large, soft leaves beside the glossy, leathery fern fronds.
Hellebore: Flowers in winter and is evergreen too.
Barrenwort: A carpet of leaves and small flowers under the same trees.
Foamflower: Light flower spikes in spring, also from North America.

Maintenance

Christmas fern: when and how to plant it?

Plant in March–May and September–October.

Plant in March–May or September–October, when the soil is neither frozen nor waterlogged.
Dig a hole twice as wide as the root ball and mix in a few spadefuls of leaf mould.
Set the plant at the same depth as in its pot, with the crown at soil level: do not bury the growing points.
Firm the soil and water in generously straight away.
Spread a layer of leaf mould around the base and keep the soil moist in the first year.

Care

Water: In the first year water weekly in dry weather. After that it usually copes by itself, even in dry summers.
Feeding: A layer of compost or leaf mould in spring is enough.
Mulching: Leaf mould in autumn keeps the soil moist and feeds the roots.
Tidying: In March cut off brown or damaged fronds; leave healthy green ones.
Position: Move it as little as possible; a quiet, permanent spot is best.

Tip: Leave the green fronds on all winter and only cut off damaged ones in March: that way it gives green all winter in a shade garden.

Christmas fern: when to prune it?

Pruning months: March.

When: In March, before the new fronds unroll. Real pruning is not needed.

How:

Cut brown, damaged or yellow fronds off at the base with sharp secateurs.
Leave healthy green fronds.
Take care of the young, rolled-up shoots in the middle of the clump.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division: In spring, carefully separate a clump with several crowns using a sharp spade and replant at once. The plant grows slowly; only divide it if necessary.
Spores: Possible but slow and a test of patience: scatter ripe spores on damp seed compost, cover with glass or plastic and wait for months.

Christmas fern: how does it get through the winter?

Hardy to −30 °C.

Very hardy, down to about −30 °C: no protection is needed, even in hard winters.
After frost the green fronds lie flat on the ground, but stay alive and green until spring.
In a pot: stand it against a wall and wrap the pot in hessian so the roots do not freeze.

Diseases and pests

Scorched fronds: Brown edges caused by too much sun or drought. Water more and choose a shadier spot.
Flattened winter fronds: Normal after frost: the fronds go limp but stay green. They do not stand up again in spring; cut them off in March.
Slugs: Young, soft fronds are nibbled in spring. Look for them in the evening and remove them by hand.
Wet feet: In heavy, wet soil the crown rots in winter. Plant in a well-drained spot or work in compost and a little sand.

Through the year

March: Cut off damaged fronds. Apply compost. Plant.
April: New fronds unroll. Plant.
May: Plant. Water in dry spells.
June: Water in dry spells.
July: Water in dry spells.
August: Water in dry spells.
September: Plant.
October: Plant. Mulch with leaf mould.
December: Rest. The green fronds decorate the garden all winter.

You and this species

Did you know?

The name Christmas fern comes from the fronds still being green at Christmas and from the small ear at the base of each leaflet, which looks like a Christmas stocking.
In North America it grows naturally on wooded slopes, where its sturdy clumps help to hold the soil.
Ferns do not form seeds but spores: they sit in small groups on the underside of the fronds.

Garden plants · All species