Not the plant you're looking for? Search over 300,000 plants
BogsAquaticHerbaceous Perennial

Iris laevigata

smooth iris

A rhizomatous perennial to 70cm in height, with erect, sword-shaped leaves and rich purple flowers 8-10cm in width, each fall with a narrow white flash at the base

Other common names
Japanese iris
Buy this plant
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
Moisture
Poorly–drained
pH
Acid, Neutral
Colour & scent
StemFlowerFoliageFruit
Spring Green
Summer Purple Green
Autumn Green
Winter
Position
  • Full sun
Aspect

South–facing or West–facing

Exposure
Exposed or Sheltered
Hardiness
H6
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
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
Temperate Asia

How to grow

Cultivation

Grow in moist to wet, deep, humus-rich, acid soil; thrives at the margins of ponds or streams. Tolerates some lime. 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
  • City and courtyard gardens
  • Cottage and informal garden
  • Flower borders and beds
Pruning

No pruning required

Pests

May be susceptible to slugs, snails and iris sawfly

Diseases

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

Get involved

The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.