• AGM plants

    AGM plants have been through a rigorous trial and assessment programme. They are:

    • Excellent for ordinary use in appropriate conditions
    • Available to buy
    • Of good constitution
    • Essentially stable in form & colour
    • Reasonably resistant to pests & diseases

Polystichum aculeatum

hard shield fern

AGM plants

AGM plants have been through a rigorous trial and assessment programme. They are:

  • Excellent for ordinary use in appropriate conditions
  • Available to buy
  • Of good constitution
  • Essentially stable in form & colour
  • Reasonably resistant to pests & diseases
  • Other common names hard shield fern
    prickly shield fern

  • Synonyms Aspidium lobatum

  • Family Dryopteridaceae

  • Genus Polystichum are mostly evergreen or semi-evergreen ferns, with short stout rhizomes and pinnately divided fronds in neat shuttlecock-like rosettes

  • Details P. aculeatum is 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

  • Plant range Europe

Characteristics

  • Foliage Evergreen

  • Habit Bushy

  • 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

Sunlight

  • Partial Shade

  • Full Shade

  • Aspect North-facing or East-facing

  • Exposure Sheltered

Soil

  • Sand

    Sand

  • Chalk

    Chalk

  • Loam

    Loam

  • MoistureWell-drained

  • SoilSand, Chalk, Loam

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 0.5-1 metres

  • Ultimate spread 0.5-1 metres

  • Time to ultimate height 2-5 years

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

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 Flower borders and beds Low Maintenance Underplanting of Roses and Shrubs City & Courtyard Gardens Coastal Cottage & Informal Garden Patio & Container Plants Rock Garden

How to care

Pruning Remove dead fronds before new ones unfurl

Pests Generally trouble free

Diseases Dense plantings may be affected by grey moulds (botrytis) or the fungal disease Taphrina wettsteiniana

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