Dahlia pinnata /ˈdeɪ.li.ə/
Common name: Garden dahlia · Pinnate dahlia
Dahlia pinnata is a tuberous-rooted perennial in the aster family, native to the highlands of Mexico. It grows from fleshy tubers into a bushy plant typically 1–1.5 m tall, with pinnately divided leaves and large composite flower heads in many colors. It is one of the two main species from which the thousands of modern garden dahlia cultivars were bred, making it the most widely cultivated dahlia species in gardens worldwide.
Care summary
Sun
Full sun, at least 6 hours daily
Water
Regular; keep evenly moist in growth
Soil
Rich, well-drained, slightly acidic to neutral
Hardiness
Zones 8–10; lift tubers in colder zones
Mature height
About 100–150 cm (3–5 ft)
Pet safe
No — toxic to cats and dogs
Difficulty
Moderate
Propagation
Propagate by dividing tubers in spring so each division carries a piece of the crown with an eye, or by basal stem cuttings taken as new shoots emerge. Root 7-10 cm cuttings in moist, free-draining compost with bottom heat; seed is also viable but will not come true to named varieties.
Fun facts
- The dahlia is the national flower of Mexico, where it was grown by the Aztecs.
- Modern garden dahlias descend mainly from crosses between D. pinnata and D. coccinea.
- The genus was named in honor of Swedish botanist Anders Dahl, a student of Linnaeus.
- Dahlia tubers were once promoted in Europe as a food crop before their ornamental value won out.