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AquaticBogsHerbaceous Perennial

Iris versicolor

blue flag

A rhizomatous perennial to 80cm in height, with narrow, erect foliage and branched stems bearing several bluish-purple flowers 6-8cm in width, the falls with a conspicuously veined white basal patch

Other common names
Boston iris
liver lily
see moreNorth American blue flag
particoloured iris
purple iris
snake lily
wild iris

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Size
Ultimate height
0.5–1 metres
Time to ultimate height
2–5 years
Ultimate spread
0.1–0.5 metres
Growing conditions
Clay
Loam
Sand
Moisture
Poorly–drained
pH
Acid, Neutral
Colour & scent
StemFlowerFoliageFruit
Spring Green
Summer Blue Purple Green
Autumn Green
Winter
Position
  • Full sun
Aspect

South–facing or West–facing

Exposure
Exposed or Sheltered
Hardiness
H7
Botanical details
Family
Iridaceae
Native to the UK
No
Foliage
Deciduous
Habit
Clump forming
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

Correct

Plant range
N America

How to grow

Cultivation

Grow in moist to wet deep, humus-rich, acid soil in full sun. Suitable for pond edges and bog gardens. See pond plants and bog gardens for further advice

Propagation

Propagate by division from mid-summer to early autumn

Suggested planting locations and garden types
  • Wildflower meadow
  • Cottage and informal garden
  • Low Maintenance
  • Flower borders and beds
Pruning

No pruning required

Pests

May be susceptible to slugs, snails and thrips

Diseases

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

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