About
Iris laevigata, the smooth iris, is a rhizomatous perennial to 70 cm with erect, sword-shaped leaves and rich-purple flowers to 10 cm across, each fall with a narrow white flash at the base, in early summer. An excellent moisture-loving iris for a bog garden, pond margin or deep, moist border.
About the genus
Iris, the irises, are rhizomatous or bulbous perennials producing narrow, often sword-shaped leaves and distinctive flowers with three large, spreading or pendent fall petals alternating with three erect standard petals. They flower from late winter to early summer in every colour of the rainbow.
Growing conditions
SunlightFull sun
Soil typeClay, Loam
Soil pHAcid, Neutral
Soil moisturePoorly-drained
AspectSouth-facing, West-facing
ExposureExposed, Sheltered
UK hardinessH6
Plant details
Plant typeBogs, Aquatic, 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
Native toTemperate Asia
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; thrives at the margins of ponds or streams. Tolerates some lime. See pond plants and bog gardens for further advice
PruningNo pruning required
PropagationPropagate by division from mid-summer to early autumn
Pest resistanceMay be susceptible to slugs, snails and iris sawfly
Disease resistanceMay be susceptible to aphid-borne viruses, bacterial soft rot and grey moulds; see Iris diseases