Dassling dahlias

Flamboyant, vibrant and exuberant, the dahlia is the late-summer flower of cottage gardens and country-house borders. It's come a long way from its wild origins in the hills of Mexico, writes Susie White

- Susie White

It's the day of the village agricultural show and the paper-covered benches of the produce marquee are lined with cakes and jellies, honey, eggs and marrows. But it's the explosion of colour that dominates the display, as huge blooms of dahlias are supported singly in glass jars. The most perfect specimens have a red card in front of them - a prized 'First' in their class.

Tall and flamboyantly coloured, these stars of the village fête and plant show are an unmissable late-summer staple of cottage gardens, humble allotments and grand stately homes alike. Dahlias draw visitors to country gardens in early autumn, including thriller-writer Agatha Christie's collection at her Greenway garden - now managed by the National Trust - beside the River Dart in Devon. You may even spot fields full of them, grown for the cut-flower industry.

Quintessentially British? In a way, and yet dahlias originate on the other side of the world - in the mountainous regions of Mexico.

SHAPE-SHIFTER

The first wild dahlias arrived in Europe in the late 18th century, sent from Mexico by a Spanish plant-finding expedition back to Madrid's Royal Botanic Gardens. Named in honour of Swedish botanist Andreas Dahl (1751-1789), dahlias were introduced to England shortly after.

Botanists and gardeners soon found that these few wild dahlia species had a remarkable property: they hybridised readily when grown from seed, producing spectacular new varieties that differed wildly in appearance, in colour, shape and size. Two hundred years or so later and the number of dahlia varieties is staggering: there are more than 50,000 named cultivars, all produced through the crossing of two or three of those original species from Mexico. Some reached outlandish proportions, bred to enormous size - great flamboyant dinner plates of floral exuberance.

FALL AND RISE