Water Irises by Sally Gregson

Irises are a many and varied tribe that hail from all corners of the world and occupy all sorts of environments. But almost without exception the beauty of their fleeting flowers has captivated man- and woman-kind throughout history.

History

Its very name is that of the ancient Greek Rainbow Goddess, Iride or Iris. Minoan murals depict irises. They were painted on the walls of ancient Egyptian temples. And the crystalline white marble of the Taj Mahal is inlaid with iris flowers in a myriad of precious stones.
Those that grow in the hills of Tuscany around Florence have given rise to the hosts of bearded irises that populate our dry, sunny gardens in May and June. Then there are many that enjoy the good life of rich damp borders, such as I. sibirica. And there are those happy living a permanently aquatic life: I. pseudacorus, I. versicolor, I. virginica and I. laevigata.
But, just to cause confusion, over the years the damp-lovers and the water irises have been hybridised and their progeny, as you might expect, prefer either damp or wet conditions, and occasionally, both.

Irises for damp sites and ponds

Our native flag iris, I. pseudacorus, can behave rather badly in captivity, but for a large, wild pond it holds its own against bulrushes and reed mace. Its variegated form is slightly more controlled, but the stripes do fade as the summer progresses. A chance hybrid with I. chrysographes occurred, and was named, in the Holden Clough Nursery in Yorkshire. It has buff-coloured flowers, with dark red-brown veining, that have a tendency to hide in the leaves. A more striking hybrid is I. pseudacorus x versicolor ‘Regal Surprise’. It’s easy to grow and produces lots of eye-catching flowers with strong amethyst falls with a black and yellow ‘signal’, that is, a central splash, and violet standards.
Iris versicolor is a native of North American swamps and wet meadows. It is lime-tolerant and also grows happily in water about 7cm to 8cm (3in) deep. The species itself has deep mauve flowers with white, strongly veined signals. But there are many lovely named varieties, such as I. versicolor ‘Rowden Melody’, with rounded, opalescent blue petals, white, veined signals with a lemon-yellow throat; and I. versicolor ‘Rowden Refrain’, with deep claret-red petals and a bright, white signal overlaid with primrose yellow. Both were bred by the Devon nursery of that name.
Also from across the ‘pond’, as its name suggests, is I. virginica. It, too, is submersible and tolerates alkalinity. It’s a slightly taller plant with broader leaves than I. versicolor. Iris virginica ‘Pond Lilac Dream’ has ghostly lilac falls, darker veins and a yellow signal. And I. virginica ‘Purple Fan’ has white flowers, heavily veined with violet-blue, and black stems.
From the lakes and marshes of China, Japan and Siberia comes I. laevigata. This, too, is easy to grow and happy in a pond, planted to a depth of about 15cm (6in). Its flowers reach about 75cm (2 1/2ft). One of the most popular varieties is I. laevigata ‘Weymouth Midnight’, whose round, velvet purple flowers have a bright white signal like a central star. Iris laevigata ‘Richard Greaney’ is soft, clear blue and a good ‘doer’. The variegated form boasts strong deep blue flowers and wears its stripes all summer.
For centuries the Japanese have grown and bred I. ensata. Their spectacular flowers, some splashed or striped, are as spectacular as one of the late Queen Mother’s hats. They are happiest in acid, boggy soil, but will grow and flower well in water too. However, they are not true water irises and should be removed from the pond during the winter or they will succumb to crown rot.