Iris Japonica

By Davis Landscape Architecture @DavisLandArch

Iris japonica (15/04/2015, Imperial Palace East Garden, Tokyo, Japan)

Position: Full sun to light shade

Flowering period: Late spring to early summer

Soil: Moist, well drained

Eventual Height: 80cm

Eventual Spread: 50cm

Hardiness: 7b, 8a, 8b, 9a, 9b, 10a

Family: Iridaceae

Iris japonica is an evergreen 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 pale blue hermaphrodite flowers have purple spots with a dark yellow crest, have a fringed edge, are up to 5.5cm across, emerge from a branched stem which emerges from the base of the leaf cluster. Its fruit is a loculicidal capsule. Its roots are rhizomes which allow this plant to spread slowly.

Iris japonica Flower (15/04/2015, Imperial Palace East Garden, Tokyo, Japan)

Iris japonica, commonly known as Fringed Iris, Butterfly Flower or Shaga, is native to Japan and China. In its native habitat it grows on grassy slopes and open forest margins.

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. Japonica is derived from the Latin meaning ‘from Japan’.

The landscape architect may find Iris japonica useful as an effective slow spreading ground cover plant with attractive flowers. This perennial is drought tolerant once established.

Ecologically, Iris japonica flowers are attractive to pollinating insects.

Iris japonica Leaf (15/04/2015, Imperial Palace East Garden, Tokyo, Japan)

The Royal Horticultural Society has given Iris japonica their prestigious Award of Garden Merit in 1994.

Iris japonica prefers well drained, humus rich, poorly drained soils. It prefers a neutral to acid pH of soil.

Iris japonica requires little maintenance. Large clumps may be divided in mid summer to early autumn.

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