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Dahlia /ˈdeɪ.li.ə/

Common name: Dahlia

Dahlia is a genus of tuberous perennials in the aster family, native to Mexico and Central America. Dahlias are celebrated for their spectacular diversity of flower forms and colors, blooming from midsummer until frost. The genus is the national flower of Mexico.

Fun facts

  • Dahlias come in nearly every color except true blue.
  • The Aztecs grew dahlias for food and used their hollow stems as water pipes.
  • There are over 57,000 registered dahlia cultivars.
  • Dahlia tubers were trialed as a potato substitute in Europe in the 19th century.

Care summary

Sun Full sun
Water Regular, deep watering; avoid waterlogged soil
Soil Rich, well-drained, slightly acidic
Hardiness Zones 8–11; lift tubers in colder climates
Mature height 0.3–1.8 m (1–6 ft) depending on variety
Pet safe Mildly toxic if ingested

Common problems

    • Lift and store tubers frost-free
    • Improve drainage before planting out
    • Wait until soil warms in late spring
    • Start tubers in pots under cover
    • Use wildlife-friendly slug pellets sparingly
    • Check plants at dusk and remove slugs
    • Trap earwigs in upturned pots of straw
    • Shake blooms before bringing flowers indoors
    • Stake plants firmly at planting time
    • Pinch tips in June for bushier growth