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Blechnum penna-marina

alpine water fern

B. penna-marina is an evergreen fern forming a mat of spreading, simply pinnate, dark green sterile fronds to 15cm in length, with narrower, erect fertile fronds, the young fronds often reddish

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Size
Ultimate height
0.1–0.5 metres
Time to ultimate height
5–10 years
Ultimate spread
0.5–1 metres
Growing conditions
Loam
Sand
Moisture
Moist but well–drained, Poorly–drained
pH
Acid, Neutral
Colour & scent
StemFlowerFoliageFruit
Spring Red Green
Summer Green
Autumn Green
Winter Green
Position
  • Full shade
  • Partial shade
Aspect

East–facing or South–facing or West–facing

Exposure
Exposed or Sheltered
Hardiness
H4
Botanical details
Family
Blechnaceae
Native to the UK
No
Foliage
Evergreen
Habit
Matforming
Genus

Blechnum are mostly evergreen ferns with erect or creeping rhizomes and simply pinnate, leathery fronds, the fertile ones usually erect, the sterile often spreading

Name status

Correct

Plant range
S Hemisphere

How to grow

Cultivation

Easy to grow in most cool, moist, shaded sites

Propagation

Propagate by sowing spores (may not come true) in mid to late summer or by division in spring

Suggested planting locations and garden types
  • City and courtyard gardens
  • Cottage and informal garden
  • Patio and container plants
  • Flower borders and beds
  • Banks and slopes
  • Underplanting of roses and shrubs
Pruning

Dead or damaged fronds may be removed as necessary

Pests

Generally pest free outdoors

Diseases

Generally disease free outdoors

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