dahlia
Dahlia Cav.
A genus overview; characteristics vary between its species.
Dahlias have a history beneath the soil as well as above it. Kew records that the Aztecs cultivated their starchy underground tubers as food. Spanish colonists brought dahlias to Europe in the eighteenth century, where they became ornamental favourites. The genus was named for the naturalist Anders Dahl. Royal Botanic Gardens Kew: Dahlia
Botanical name
Kew recognizes Dahlia Cav. as a genus in Asteraceae. Kew POWO: Dahlia
Recognizing the plant
These perennials grow from underground tubers. Some species have soft green stems, while others develop woody ones. Cultivation has produced an extraordinary variety of flower-head shapes, from open, star-like arrangements to dense balls and waterlily-like forms. Colours include white, yellow, orange, red and purple. The underground structures can be divided to produce additional plants. Royal Botanic Gardens Kew: Dahlia
Seasonality across the genus
Kew Gardens, London, cultivated display
At Kew Gardens in London, June through September is listed as the best period to see dahlia flowers in the collection. Royal Botanic Gardens Kew: Dahlia
Native range
The native genus extends from Mexico through Central America to Colombia. Kew describes its upland setting in pine-oak woodland, with populations occurring between about fifteen hundred and thirty-seven hundred metres elevation. Kew POWO: DahliaRoyal Botanic Gardens Kew: Dahlia
Botanical sources
Reviewed 2026-10-11. Seasonal development varies with location and growing conditions.