Dahlia

Where it grows

Wild dahlias are native to the high mountain meadows and cloud forests of Mexico and Guatemala, where the Aztecs grew the tubers as a food crop called cocoxochitl. Spanish botanists sent the first plants to Madrid in 1789. The dahlia is the national flower of Mexico.

How to recognise it

A stout, hollow-stemmed perennial growing fifty centimetres to two metres tall from a clump of pencil-thick tubers. Composite flowers range from small two-centimetre pompons to the dinner-plate “AA” giants over twenty-five centimetres across, in officially classified forms: single, anemone, ball, decorative, cactus, waterlily, and collerette.

Garden & cultural uses

Modern cultivars number in the tens of thousands. Tubers must be lifted in cold-winter regions after the first hard frost and stored cool, dry, and frost-free until spring. Once spurned by colour-purist designers, dahlias returned to fashion in the 2010s with selections such as Cafe au Lait and Bishop of Llandaff.

In history

The dahlia is named for Anders Dahl, an eighteenth-century Swedish botanist and student of Linnaeus, although Dahl himself never saw the living plant.