Polystichum aculeatum

RHS Plant Profile

hard shield fern

Other common names

prickly shield fern

Synonyms

Aspidium lobatum

Ferns

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An evergreen fern forming a neat rosette of bipinnate, erect or arching, leathery dark green, narrowly lanceolate fronds to 90cm long, with slightly prickly pinnules

Position

Full shade, Partial shade

Soil Types

Chalk, Loam, Sand

Max Height

0.5-1 metres

Max Spread

0.5-1 metres

Size

Time to Maturity: 2–5 years
Max Spread: 0.5-1 metres
Max Height: 0.5-1 metres

Growing Conditions

Chalk Loam Sand

Moisture: Well–drained
pH: Acid or Alkaline or Neutral

Position

Full shade Partial shade

Aspect: North–facing or East–facing
Exposure: Sheltered
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

H1A: under glass all year (>15C)
H1B: can be grown outside in the summer (10 - 15)
H1C: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20): H7

Colour & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Dryopteridaceae
Native to GB/Ireland: Yes
Foliage: Evergreen
Habit: Bushy
Genus: Polystichum are mostly evergreen or semi-evergreen ferns, with short stout rhizomes and pinnately divided fronds in neat shuttlecock-like rosettes
Name Status: Correct
Plant Range: Europe, N Africa, Middle East

How to Grow

Cultivation

Grow in fertile, humus-rich well-drained soil in deep or partial shade; protect the crowns from excessive winter wet and provide a mulch around the crown to prevent crown drying out. See how to grow ferns for further advice

Propagation

Propagate by spores, sow spores at 15-16°C (59-61°F) when ripe. Divide rhizomes in spring or detach fronds bearing bulbils in autumn

Suggested planting locations and garden types

Cottage and informal garden
Patio and container plants
Rock garden
City and courtyard gardens
Coastal
Low Maintenance
Underplanting of roses and shrubs
Flower borders and beds

Pruning

Remove dead fronds before new ones unfurl

Pests

Generally pest-free

Diseases

Dense plantings may be susceptible to grey moulds (botrytis) or the fungal disease Taphrina wettsteiniana