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Herbaceous Perennial

Iris 'Blue King' (Sib)

A rhizomatous, clump-forming, herbaceous perennial with linear, strap-like, bright green leaves and erect stems, up to 1.2m tall, bearing deep violet-purple flowers with veined yellow throats from May into June. Perfect for planting beside water, such as a pond

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Size
Ultimate height
1–1.5 metres
Time to ultimate height
2–5 years
Ultimate spread
0.1–0.5 metres
Growing conditions
Chalk
Clay
Loam
Sand
Moisture
Moist but well–drained
pH
Acid, Alkaline, Neutral
Colour & scent
StemFlowerFoliageFruit
Spring Purple Yellow Green
Summer Purple Yellow Green
Autumn Green
Winter
Position
  • Full sun
  • Partial shade
Aspect

South–facing or East–facing or West–facing

Exposure
Exposed or Sheltered
Hardiness
H7
Botanical details
Family
Iridaceae
Native to the UK
No
Foliage
Deciduous
Habit
Clump forming, Columnar upright
Potentially harmful
Harmful if eaten. Wear gloves and other protective equipment when handling. Pets: Harmful if eaten. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Genus

Iris may be rhizomatous or bulbous perennials, with narrow leaves and erect stems bearing flowers with 3 large spreading or pendent fall petals, alternating with 3 erect, often smaller, standard petals, in late winter, spring or early summer

Name status

Unresolved

Horticultural Group
Sibirica irises are rhizomatous perennials, to 1.2m tall, with narrow leaves and erect stems bearing up to 5 beardless flowers 6-7cm wide in early summer. Form and colour vary considerably among cultivars

How to grow

Cultivation

Grow in any moist but not waterlogged, neutral to slightly acidic soil in full sun or partial shade. In drier soils, dig in well-rotted manure before planting and apply as a mulch each spring

Propagation

Propagate by division of the rhizome shortly from mid-summer to early autumn. See dividing irises

Suggested planting locations and garden types
  • City and courtyard gardens
  • Cottage and informal garden
  • Coastal
  • Low Maintenance
  • Cut flowers
  • Flower borders and beds
  • Wall side borders
Pruning

Cut back old flower stems after flowering and remove dying foliage in autumn

Pests

May be susceptible to slugs and snails

Diseases

May be susceptible to aphid-borne viruses, bacterial soft rot and grey moulds; see Iris diseases

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