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

Iris pseudacorus
  • RHS Plants for pollinators

yellow iris

A vigorous herbaceous perennial, forming extensive colonies to 1.5m in height, with waxy grey-green leaves and bright yellow flowers up to 10cm in width, the falls with brown veining in the centre, in mid and late summer

Other common names
daggers
flagon
see moreJacob's sword
water flag
water skegs
yellow flag
yellow fleur-de-lis
Buy this plant
Size
Ultimate height
1–1.5 metres
Time to ultimate height
2–5 years
Ultimate spread
1–1.5 metres
Growing conditions
Clay
Loam
Moisture
Poorly–drained
pH
Acid
Colour & scent
StemFlowerFoliageFruit
Spring Green Grey Silver
Summer Yellow Green Grey Silver
Autumn
Winter
Position
  • Full sun
  • Partial shade
Aspect

South–facing or East–facing

Exposure
Exposed or Sheltered
Hardiness
H7
Botanical details
Family
Iridaceae
Native to the UK
Yes
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
Europe Africa Asia

How to grow

Cultivation

Grow in wet, deep, acid, humus-rich soil in full sun or partial shade. It thrives at the margins of large ponds or streams; has the potential to become a nuisance if not managed well so plant with care

Propagation

Propagate by division from midsummer to early autumn, plant immediately in flowering positions

Suggested planting locations and garden types
  • Coastal
  • Cottage and informal garden
  • Wildflower meadow
  • Wildlife gardens
Pruning

Remove any dying foliage in autumn, old flower stems can be cut down after flowering

Pests

May be susceptible to slugs, snails and thrips

Diseases

May be susceptible to aphid borne viruses, bacterial soft rot and grey moulds (Botrytis)

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.