Position: Full sun to light shade
Flowering period: Late spring to early summer
Soil: Moist, well drained
Eventual Height: 70m
Eventual Spread: 60cm
Hardiness: 7a, 7b, 8a, 8b, 9a, 9b
Iris douglasiana is an evergreen herbaceous perennial with an erect clump forming habit. Its dark green leaves are ensiform with entire margins and gradually narrowing to a point, up to 60cm long and 2cm across at their base. Its pale purple hermaphrodite flowers are up to 10cm across, emerge from a branched stem which emerges from the base of the leaf cluster. Its fruit is a loculicidal capsule and up to 4cm long. Its roots are below ground rhizomes, are up to 1cm across and allow this plant to steadily spread.
Iris douglasiana, commonly known as the Douglas Iris, is native to western coastal regions of USA. In its native habitat it grows in meadows, grasslands and open woods in coastal regions.
The etymological root of the binomial name Iris is derived from the Greek word for a rainbow, referring to the wide variety of flower colours found among the many species. Douglasiana is named after David Douglas (1799 – 1834), a Scottish botanist.
The landscape architect may find Iris douglasiana useful as a herbaceous perennial with attractive flowers. This perennial will tolerate occasional flooding.
Ecologically, Iris douglasiana is attractive to bees and pollinating insects.
Iris douglasiana prefers moist, humus rich, well-drained soils. It prefers a neutral to acid pH of soil, although it will tolerate most pH.
Iris douglasiana requires little maintenance. Large clumps may be divided in autumn.