About
Iris douglasiana, the Douglas iris, is an evergreen perennial to 70 cm with narrow, dark-green leaves and usually branched stems bearing purple or lavender-blue flowers to 10 cm across in late spring, the falls often with a white basal patch. A beautiful Pacific coast iris for a well-drained, partly shaded 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, Partial shade
Soil typeClay, Loam, Sand
Soil pHAcid, Neutral
Soil moistureMoist but well-drained, Well-drained
AspectSouth-facing, North-facing, West-facing, East-facing
ExposureSheltered
UK hardinessH6
Plant details
Plant typeHerbaceous Perennial
HabitBushy
FoliageEvergreen
Height0.5-1 metres
Spread0.1-0.5 metres
Time to full height2-5 years
Suggested usesCoastal, City and courtyard gardens, Cottage and informal garden
Native toNorth W America
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
CultivationThe most easily grown of the Pacific Coast Iris tolerating slightly drier and more alkaline soils
PruningRemove dead foliage, old flower stems can be cut down after flowering
PropagationPropagate by seed or division in spring
Pest resistanceMay be susceptible to slugs, snails and thrips
Disease resistanceMay be susceptible to aphid-borne viruses, bacterial soft rot and grey moulds; see Iris diseases