The Cayeux tapestry: How one French family is growing iris hybrids fit for the Queen

They are the Hollywood glamourpusses in the world of floral loveliness – tall and slender with a divine set of tucks and ruffles in all the right places. And, like the best film noir heroines, they even have a dark side: that brooding eroticism captured in Georgia O'Keeffe's photos. Even their name is back in fashion: thanks to Palmer, Strubegger and Van Herpen, Irises are à la mode.

Chelsea Flower Show has always been a great place to see bearded irises, at their best in this very week of May. And in 2010, the flowers will be on display in bigger numbers than ever before, as nurseries from both sides of the Channel show off their new introductions. Particularly worth seeing are the glories of Richard Cayeux's stand, where gorgeous stems are unwrapped from French newspapers at 5am on the morning of the Queen's visit.

Richard is the fourth generation to run the family nursery; the Cayeuxs have been breeding irises in France since 1895. Nowadays, you can stop on a trip down to the south and see 55 acres of fields in Gien, on the Loire River, each full of new varieties, for Cayeux is an obsessive hybridiser. He spends the early summer walking up and down the rows pondering what new beauties to create, then passes the cold winter thinking up their names. He's created flowers in honour of all three of his daughters – the wonderfully titled Astrid C, Sixtine C and Belle Hortense – plus a whole set of famous French stallions (by which I mean horses, not Johnny Hallyday).

The asymmetric construction of the iris is part of its glamour. Instead of one flowerhead of round daisy petals, the thick green stalk bears buds all the way up. They come in shades from bluey-white through rusty-orange to darkest purply-black, set off by zingily colourful patterning on the petals, with a final touch in the form of the "beard", a rude-looking fur that disappears into the flower, a landing guide for hopeful bees.

Irises are hardy types, but these huge beauties need special growing conditions, and one requirement in particular is essential: their rhizomes, looking much like a piece of undistinguished supermarket ginger, must be baked all summer long after flowering. Without this hot spell, the plants are badly hit by snail attacks and other horticultural hassles, stop flourishing and eventually disappear. The only way to build up a little colony is to guarantee them this, which means not interplanting them with anything that will create shade. You suddenly see why the baking fields of central France might be an ideal home. n

For the Cayeux catalogue of 550 varieties with growing hints, see iris-cayeux.com or call 0800 096 4811. Visitors to France are welcome to visit the nursery, open until 4 June, with peak flowering expected this week

Have a field day

Claire Austin Hardy Plants

A master bearded-iris grower, Claire opens her fields in Shrewsbury from 29-30 May and 4-5 June, while her online catalogue includes a selection of historic varieties that are more than 100 years old. claireaustin-hardyplants.co.uk

Seagate Irises of Lincolnshire

Julian and Wendy Browse open their trial fields from 10am to 5pm daily, and in early June expect to have 600 varieties of iris in flower at the same time. irises.co.uk

Iris of Sissinghurst

Run by Sue Marshall, who grows Cayeux's plants for display at Chelsea. Her online selection of 150 varieties includes my favourite, the "Carnaby". Her fields open from 5-6 June. irisofsissinghurst.com