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Know your: Iris

Photo - Artkwin/

When we say iris do you think Van Gogh blue iris, or romantic bearded iris in shades to perfectly match old roses? Or does iris suggest cheery yellow flowers lining the dam? No wonder we all conjure a different image - there are about 300 species in the iris family. Here are a handful of the best for gardeners.


Bearded iris

Iris germanica

ID: Tall bearded (TB) are the most popular in this group. Many are bi-coloured with the central ‘standard’ petals and pendulous ‘fall’ petals in contrasting colours. Grey-green leaves are slender and sword-shaped. Most flower in spring; some (such as deep blue ‘Victoria Falls’) repeat-flower.

Grow: Plant the rhizome in full sun, in light, well-drained soil, at ground level. Don’t buy it or it will rot. Secure with coat hanger wire until roots develop. Find some beauties at


Blue flag iris

Iris versicolor

ID: This semi-aquatic plant has deep green, narrow, sword-shaped leaves and blue-violet flowers on 1m stalks from late spring to early summer. There are many species of blue flag iris found along the edges of swamps, wet meadows and stream banks or in forested wetlands.

Grow: This hardy plant is very easy to grow and prefers moist, deep, humus-rich, acid soil in full sun.

Photo - Elena Elisseeva/


Yellow flag iris

Iris pseudacorus

ID: Clumps of tall, slender foliage produce spikes of golden, scented flowers in summer. This is the Fleur de Lys iris, used as a symbol of the French kings since the 12th century.

Grow: these iris are happiest in shallow water and full sun. In cold areas they will die down during winter but in warm temperate regions like Sydney they remain semi-evergreen. Find them at and

Photo - Rainbow Ridge Nursery


Japanese iris

Iris ensata and Iris kaempferi

ID: These iris line ponds and streams in Japan. Their leaves are taller and thinner than those of bearded iris, and feature a distinct rib. The flowers, on 90cm stems, are white, blue or lilac.

Grow: Japanese iris love to be wet so plant them in sunshine on the edge of a pond. They can also be planted in containers. Feed with liquid manure in the lead-up to the spring flowering. Every three years lift and divide them after flowering.

Photo - TOMO/


Louisiana Iris

Iris hexagonae

ID: These water-loving plants from the Louisiana swamps flower on tall stems in spring. The impressive flowers are beardless but with standard and fall petals, which may be recurved or flat; single or double; ruffled, lacy or plain with varied patterns, colours and markings.

Grow: These iris are happiest in standing water or in boggy areas and can be grown in the garden as long as they are given plenty of water. Establish plants in pots before planting around dams or immersing in ponds. Find them at

Photo - Rainbow Ridge Nursery


Californian iris

Iris chrysophylla

ID: An iris native to of the west coast of the US, this one flowers in a huge range of colours. The blooms float above the foliage from early to mid-spring.

Grow: Plant in semi-shade, and feed in late autumn and early spring. Don’t let them dry out. Mass plant along paths and driveways, or grow them in pots. Find them at

Photo - Rainbow Ridge Nursery


Dutch iris

Iris reticulata

ID: This is the iris familiar from florists. They grow from small bulbs and flower in spring in shades of light blue, yellow, white and purple.

Grow: Plant bulbs in autumn, in groups. They like plenty of sun and rich, well-drained soil. Add some compost or soil conditioner before planting out in autumn. Dutch iris can be left in the ground for year-after-year flowering. Cut when in bud for long-lasting cut flowers. 

Photo - mikeledray/Shutterstock
Text: Sandra Ross

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Author: Sandra Ross