Content Detail

Reminiscent of an old-fashioned garden, delphiniums have tall flower spikes in colors from white to pink, and light lavenders to intense blue. The flowers have five sepals with the topmost one forming a spur behind the flower. They are well-suited to perennial borders, but can also be used as specimen plants. In the Midwest, they are relatively short-lived. Although the straight species is seldom seen, many of the hybrid garden delphiniums are part of the lineage of this species.

  • Family (English) Buttercup
  • Family (botanic) Ranunculaceae
  • Tree or plant type Perennial
  • Native locale Non-native
  • Size range Large plant (more than 24 inches)
  • Light exposure Full sun (6 hrs direct light daily)
  • Hardiness zones Zone 3, Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7
  • Soil preference Moist, well-drained soil
  • Season of interest mid spring, late spring
  • Flower color and fragrance Blue, Purple
  • Shape or form Upright
  • Growth rate Moderate

Size and form:

Delphinium is an upright perennial growing 4 to 6 feet high.

Native geographic location and habitat:

Mountains of central and eastern Europe and central Asia.

Attracts birds or pollinators:

The blooms attract both hummingbirds and butterflies.

Leaf description:

Large, palmate leaves have five to seven lobes. The leaf size diminishes as the location moves up the stalk.

Flower description:

Pink, white, blue, or lavender flowers in showy spikes. The flowers have five sepals, the topmost of which forms a spur that sticks out behind the flower. Often the flowers have two small petals at the center which are white or brown called ‘the bee.’

Fruit, cone, nut, and seed descriptions:

Each flower produces three or more achenes (small, dry fruit) that contain a single seed.

Plant care:

All parts of the plant are poisonous, so do not ingest. Plant in full sun in moist, well-drained soil. Performing best in fertile soil, delphinium should be protected from the wind and may need staking as the growing season progresses.

List of pests, diseases, and tolerances:

Powdery mildew, bacterial disease, root and crown rots, slugs, and snails. Deer and rabbit resistant, as all parts of the plant are poisonous.

Donate

Your support is vital to the Arboretum, where the power of trees makes a positive impact on people’s lives.

Make a gift