The cultivation of Siberian iris (Iris sibirica)

Walter Gardens Inc. Siberian iris have been cultivated since at least the sixteenth century. They are prairie hardy, long-lived and easy to grow.

by Sara Williams

Native to central and eastern Europe, the Balkan region, the Caucasus, Iran, and Russia, Siberian iris have been cultivated since at least the sixteenth century. They are prairie hardy, long-lived and easy to grow.

Beardless and of a more delicate appearance than the bearded iris, they form erect clumps of 60 to 120 cm (24-48 in.). Their grassy leaves are narrow, strap-like, and slightly arching and the foliage looks good throughout the season. The six-petalled flowers bloom in June in blue, purple, wine, lavender, pink, white, and yellow as well as various bicolours.

Plant Siberian iris in full sun or partial shade in deep soil well amended with generous amounts of organic matter. The soil should be evenly moist but well drained.

They are an excellent addition to the perennial border or massed near ponds or streams. Siberian irises are easily increased by division in early spring or after flowering.

Among the many varieties are:

          •        ‘Blue King’ is 60 to 90 cm (24-36 in.) tall, with blue flowers.

          •        ‘Butter and Sugar’ has white standards (three upright petals) and creamy yellow falls (three downward facing petals) on 65 to 70 cm (26-28 in.) stems.

          •        ‘Caesar’s Brother’ is a deep royal blue with a golden throat on a 90 to 100 cm (35-40 in.) plant.

          •        ‘Chilled Wine’ has wine-carmine flowers with blue in the centre overlaid with dark veining on plants of about 60 cm (24 in.).

          •        ‘Concord Crush’ has double, violet blue flowers with a white and gold blaze. It grows 60 to 70 cm (24-27 in.) high.

          •        ‘Contrast in Styles’ has light purple standards with wine-purple falls with white signals (area surrounding the beard) edged in blue on 70 to 86 cm (28-34 in.) plants.

          •        ‘Kaboom’ has 15 cm (6 in.), double, blue-violet flowers with a yellow-and-white blaze in the centre. It grows to 80 cm (32 in.).

          •        ‘Magnum Bordeaux’ – wide ruffled royal purple with blue-violet signal and white signal lines, 80 cm (32 in.).

          •        ‘Miss Duluth’ – red-purple, 60 cm (24 in.).

          •        ‘Pink Haze’ has lavender-pink flowers on 80 to 90 cm (32-35 in.) stems.

          •        ‘Ruffled Velvet’ is purple with a white-and-gold blaze on a relatively short plant of 55 to 60 cm (21-24 in.).

          •        ‘Salamander Crossing’ – pale lavender standards, pale yellow heavily speckled falls, 107 cm (42 in.).

          •        ‘Sapphire Royale’ – dark sapphire blue, darker falls, 80 cm (32 in.).

          •        ‘Sky Wings’ is pale blue with a yellow blaze on 60 to 90 cm (24-36 in.) stems.

          •        ‘Strawberry Fair’ has lavender-pink standards and magenta-pink falls with a white signal edged in blue on 60 to 75 cm (24-30 in.) stems.

          •        ‘White Magnificance’ – very large white self, 107 cm (42 in.).

Other Species

          •        Yellow flag iris(I. pseudacorus), native to Europe and Asia, is about 120 cm (48 in.) in height and found in shallow water and marshy ground. It has yellow flowers and will self-seed prolifically, especially in wet areas. It is considered an invasive species in much of Canada and its planting is discouraged.

          •        Arctic Iris (I. setosa var. arctica) is native to Siberia and Alaska. While it is thought of as a wetland plant, it thrives under normal garden conditions. Low and grassy, it is 15 to 30 cm (6-12 in.) tall and can be used as a ground cover, at the front of the border, or in a sunny rock garden. It has light blue flowers. I. setosa var. indigo has dark violet-blue flowers and is a little taller at 30 to 45 cm (12-18 in.).

          •        Blue flag iris (I. versicolor) is native to North America and about 60 cm (24 in.) in height, with light bluish-purple flowers in late spring. Its native habitat is at the water’s edge, but it thrives under average garden conditions. ‘Gerald Darby’, one of its varieties, has purplish foliage in spring and black flower stalks.

Sara Williams is the author of many books including Gardening Naturally with Hugh Skinner, Creating the Prairie Xeriscape, and with Bob Bors, Growing Fruit in Northern Gardens. She gives workshops on a wide range of gardening topics throughout the prairies.

This column is provided courtesy of the Saskatchewan Perennial Society (SPS; Check our website ( or Facebook page ( for a list of upcoming gardening events.