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 irisliver lily
see moreNorth American blue flag
particoloured iris
purple iris
snake lily
wild iris
Size
Ultimate height
0.5–1 metresTime to ultimate height
2–5 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Moisture
Poorly–drainedpH
Acid, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Green | |||
|---|---|---|---|---|
| Summer | Blue Purple | Green | ||
| Autumn | Green | |||
| Winter |
Position
- Full sun
Aspect
South–facing or West–facing
Exposure
Exposed or Sheltered Hardiness
H7Botanical details
- Family
- Iridaceae
- Native to GB / Ireland
- 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
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.