About
This clump-forming perennial to 60cm in flower, erect, strap-like green leaves with a prominent midrib rise beneath upright stems bearing flat, 15cm wide, double, dark blue-purple blooms with a yellow centre, in summer.
About the 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
Growing conditions
SunlightFull sun, Partial shade
Soil typeClay, Loam
Soil pHAcid, Neutral
Soil moisturePoorly-drained, Moist but well-drained
AspectSouth-facing, West-facing, East-facing
ExposureExposed, Sheltered
UK hardinessH6
Plant details
Plant typeBogs, Herbaceous Perennial
HabitClump forming
FoliageDeciduous
Height0.5-1 metres
Spread0.1-0.5 metres
Time to full height2-5 years
Suggested usesCity and courtyard gardens, Cottage and informal garden, Wildlife gardens
ToxicityHarmful 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
Care notes
CultivationGrow in moist to wet, deep, humus-rich, acid soil, plant rhizomes 7.5cm deep; it thrives at the margins of ponds or streams, but avoid winter waterlogging
PruningRemove any dying foliage in autumn, old flower stems can be cut down after flowering
PropagationPropagate by division of rhizomes after flowering from midsummer to early autumn every three years
Pest resistanceMay be susceptible to slugs, snails, iris thrip and iris sawfly
Disease resistanceMay be susceptible to aphid-borne viruses, bacterial soft rot and grey moulds; see Iris diseases