Water Iris

In the Spring a livelier iris changes on the burnish'd dove; In the Spring a young man's fancy lightly turns to thoughts of love.

The iris is a plant inseparable from water in the landscape. For many of us, its image was cast by Monet in his paintings of the garden at Giverny, a celebration of the unique dialogue between plants and water. Iris was the Greek goddess of the rainbow, perhaps an allusion to the diversity of colour in the genus.

The iris has been noted and used by herbalists and horticulturists, and has featured prominently in art and iconography through recorded history. The image of the fleur-de-lis, meaning 'the flower of the lily', is drawn from the flower of the common yellow flag iris, I. pseudacorus, one of the species valuable for marginal planting. Construed as 'fleur-de-lys', suggesting 'flower of Louis', the symbol was used on the French royal standard until Napoleon banned the image with the Revolution. The name was later anglicised to 'flower-de-luce', until the present name gained acceptance in the eighteenth century. Irises are depicted among roses, poppies, peonies and other purely aesthetic garden plants in delightful early Persian miniature paintings of garden scenes and have appeared widely in the art of the ancient civilisations and empires of China and India.

The iris a complex and variable genus of some 300 species spread across temperate zones of the northern hemisphere. Those that have adapted to living at the water's edge are of the beardless type, growing from rhizomes rather than bulbs. But like all irises, they prefer an acidic, organic soil and some shelter from hot, sunny winds and afternoon summer sun.

Plants can be propagated by lifting and dividing the clumps every few years or when they become overcrowded. The rhizome is cut into sections, each with healthy roots and a fan of leaves which should be cut back by about half to reduce stress through water loss. Unlike those of bearded irises, the rhizomes of beardless types used in marginal planting should be kept covered below the soil level.

The Japanese water iris, Iris ensata (syn. I. kaempferi), along with hundreds of cultivars, is well known as a cut flower and makes an ideal bog garden plant in full sun or partial shade. Its sword-like leaves die back in May, reshooting in July to August, to reach a height of about 90 cm.

Flowering takes place over November and December, with two to four flowers per stem, in various combinations of white, pale blue, mauve, maroon, purple and pink. I. laevigata and its cultivars are closely related to I. ensata and enjoy similar conditions.

The Louisiana irises can be traced to three species native to the bayou country of Louisiana, making them a good choice for our warmer climates. They are highly adaptable plants which will grow in moist garden soils, bog gardens or standing in water. Ambivalent about sunlight, they prefer some afternoon shade in summer. Although they are spectacular in the garden, they are possibly best known as cut flowers, blooming from late October to December in a huge range of colours including white, yellows, pinks, bronzes, coppers, blues and lavenders.

The yellow flag, I. pseudacorus, is a common sight in wetlands and riverbanks throughout Europe and the Mediterranean. The species and its cultivars are tough, aquatic or marginal plants for full sun or semi-shade. Plant sparingly as they are vigorous growers that increase quickly without intervention.

Iris 'Roy Davidson'

Specialist waterplant suppliers in Australia

Austral Watergardens, 1295 Pacific Highway, Cowan, NSW 2081.
Dragonfly Aquatics, Forrest, Vic. 3236. (03) 5236 6320. A wide range of aquatic plants available by mail order.
Everglades Watergarden Supplies, 216 Abbotts Road, Bootawa, NSW. 2430
www.everglades.com.au (02) 6553 0700, Fax (02) 6553 0744
L.R. & N.R. Gedye Pty Ltd, 37­41 Elizabeth Street, Doncaster East, Vic. 3109. 1800 036 102. Waterlilies, iris and other waterplants; pond equipment including punmps, fibreglass cascades and pools.
Ledora Watergardens, 851 Pacific Highway, Mt Kuring-gai, NSW 2080. (02) 9456 1163.
Lotus Watergardens, Gardenworld, 810­834 Springvale Road, Keysborough, Vic. 3173. (03) 9798 4599, (03) 9701 6038.