Celebrating dahlia season – here’s 10 facts you might not have known about these gorgeous late season flowers

By alyshurn

Published: Tuesday, 29 August 2023 at 12:25 PM

10 things you (possibly) didn’t know about dahlias

Who can resist dahlias in their diversity of colour, size and style – late summer just wouldn’t be the same without at least one dahlia in the garden somewhere. They are great plants to grow in a cut flower garden and their beautiful flower heads often last well into the autumn, extending the flowering season.

Here’s a list of interesting facts about dahlias

They were discovered by the Spanish

It was 16th-century Spanish botanists who noted dahlias growing wild on the hillsides of Mexico, although paintings and illustrations suggest that native civilisations had been cultivating and breeding them much earlier.

Some dahlias are edible

Dahlias were originally grown as a food crop for their edible tubers. Gardeners and television presenter James Wong suggests they taste like a cross between carrot, celery and potatoes.

Early botanists admired their mystic appeal

In 1776 the French botanist Nicolas-Joseph Thiéry de Menonville was sent to Mexico. His papers stated that he was in search of the botanicals used in the treatment of gout. In fact he had been charged with stealing the cochineal insect valued for its scarlet dye. As well as collecting the insect and the prickly pear they depend on, his notes tell of the strangely beautiful flowers he had seen growing in a garden in Oaxaca – dahlias.

One of the earliest plants to be introduced to Europe

Dahlia coccinea was one of the first species to be introduced into Europe from Mexico in 1789, to the Royal Botanic Gardens in Madrid.

Swedish nomenclauture

Abbe Cavanilles (director of Real Madrid Botanical Garden) named the Dahlia after Anders Dahl, the Swedish botanist, who had died two years previously.

Part of the daisy family

Dahlias belong to the Asteraceae (Aster) family along with daisies and sunflowers.

Rapid growth in cultivars

Cavanilles noted three dahlia cultivars Dahlia pinnata, D. rosea and D. cochinea. Now there are 5,692 records (including species and cultivars) on the RHS’s horticultural database, with new cultivars constantly being bred.

Dahlias come in all shapes and sizes

Dahlias range from dwarf plants ideal for bedding, to giants such as Dahlia imperialis found growing in the wild from Guatemala to Colombia where it can grow upwards of 6m tall.

Some Dahlias are huge!

Some cultivars have flowers that reach beyond dinner plate size at 35cm across.

Dahlias are an award-winning garden plant

To date the Royal Horticultural Society has given125 dahlia cultivars an Award of Garden Merit, noting them as particularly garden worthy.

• For a practical guide to growing dahlias try The Plant Lover’s Guide to Dahlias by Andy Vernon (Timber Press, £17.99. ISBN 978-1604694161) . The book gives growing tips, ideas on planting combinations, tips on how to undertake your own breeding and a good listing of where to see dahlias at their best and suppliers.