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Monkshood

Aconitum napellus

Common names:
Monkshood, Helmet flower, Wolfsbane

Content Detail

Monkshood is an upright, 2 to 4 foot high perennial with lovely blue-violet, spiked flowers that appear in mid-to-late summer. The distinctive, helmet-shaped flowers resembling the hood of a monk’s cape, thus the common name. All parts of this plant are poisonous, especially the bulbous roots, and should be planted with caution, especially near vegetable gardens and where children play.

  • Family (English) Buttercup
  • Family (botanic) Ranuculaceae
  • Tree or plant type Perennial
  • Native locale Non-native
  • Size range Medium plant (12-24 inches), Large plant (more than 24 inches)
  • Light exposure Partial sun / shade (4-6 hrs 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
  • Tolerances Occasional flooding
  • Season of interest midsummer, late summer, early fall
  • Flower color and fragrance Blue, Purple
  • Shape or form Upright
  • Growth rate Slow
  • Wildlife Game mammals

Size:

Monkshood is an upright, erect perennial reaching 2 to 4 feet high and 1 to 2 feet wide.

Native geographic location and habitat:

Found in moist pastures and mountain areas in Central and Western Europe and Asia.

Leaf description:

Alternate, dark green, 3 to 5 inches wide, palmately-shaped, and divided at base.

Flower description:

The flowers are held in upright, terminal spikes, violet-blue with enlarged upper sepal, resembling the hood of a monk’s cape. Flowers appear in mid-to-late summer. The flowers similar to Delphinium, but Monkshood has 2 petals, whereas Delphinium has 4.

Fruit description:

The fruit is a follicle and of limited ornamental appeal.

Plant Care:

All parts of monkshood are poisonous, especially the roots, so wear gloves and take precautions when working with this plant. It grows best in part shade in a moist, rich organic soil. If planted in sun, maintain soil moisture to avoid scorch. Water in dry periods. Best left undisturbed and is slow to recover from division. Plants prefer cooler growing conditions and will not tolerate hot summer temperatures. Deadhead flowers to promote secondary growth. Cut back foliage in spring to promote bushier growth. Staking may be necessary to control height.

List of pests, diseases and tolerances:

Monkshood is prone to mites, powdery mildew, verticillium wilt, and crown rot in wet soils. Resistant to deer and rabbits.

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