Iris setosa

Iris setosa (23/06/2013, Kew Gardens, London)

Position: Full sun to light shade

Flowering period: Early summer

Soil: Moist, well drained

Eventual Height: 90cm

Eventual Spread: 60cm

Hardiness: 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b

Family: Iridaceae

Iris setosa is a semi evergreen, erect, herbaceous perennial with a clump forming habit. Its  mid green leaves are lanceolate with entire margins and gradually narrowing to a point, up to 60cm long and 3cm broad at their base. Its blue hermaphrodite flowers emerge from a branched stem which emerges from the base of the leaf cluster and is up to 90cm tall. Its fruit is a loculicidal capsule. Its roots are below ground rhizomes which allow this plant to steadily spread.

Iris setosa, commonly known as the Blue Flag Iris or Beachhead Iris, is native to north west North America and coastal regions of east Asia, including Japan. In its native habitat it grows in wet peaty meadows, riversides and open woods, occasionally in brackish bogs.

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. Setosa is derived from the Latin Seta meaning ‘bristle’.

Iris setosa Flower (23/06/2013, Kew Gardens, London)

The landscape architect may find Iris setosa useful as an effective spreading ground cover plant with attractive flowers particularly in damp peaty locations. It will tolerate saline soils.

Ecologically, Iris setosa is attractive to bees and pollinating insects.

Iris setosa prefers moist, fertile, well-drained soils. It tolerates most pH of soil. It will tolerate wet soils.

Iris setosa requires little maintenance. Large clumps may be divided in autumn.