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ALLIUM cernuum

Image of Allium cernuum

James H. Schutte

Family

Liliaceae

Botanical Name

ALLIUM cernuum

Plant Common Name

Nodding Onion

General Description

Distinguished by its nodding flower heads and its relatively long season of bloom, this small to medium-sized bulbous perennial is among the most popular of the ornamental onions. It is native to slopes, prairies, and open woodlands throughout much of North America.

Plants form clumps of flattened, arching, grass-like leaves, arising from narrow bulbs with grayish, fibrous coats. In late spring and summer, bulbs produce solitary flower stems, each bearing a domed cluster of 20 to 30 purple-pink to white flowers at its down-curved apex. The cup-shaped blooms attract butterflies and bees. Some bulbs produce a succession of flower stems, blooming for several weeks in all. Small tan capsules follow the flowers, casting seed which often germinates. The leaves do not wither at bloom time, as do those of most other onions. All parts of the plant are nearly odorless.

Plant this charming ornamental onion in full to partial sun and well-drained soil. It works well in mixed borders, wildflower plantings, and cottage gardens. A highly variable species, it has given rise to several named varieties and hybrids, including the white-flowered 'Leo'.

Characteristics

  • AHS Heat Zone

    9 - 1

  • USDA Hardiness Zone

    3 - 9

  • Plant Type

    Bulb or Corm or Tuber

  • Sun Exposure

    Full Sun, Partial Sun

  • Height

    1'-2' / 0.3m - 0.6m

  • Width

    8"-12" / 20.3cm - 30.5cm

  • Bloom Time

    Late Spring, Early Summer, Summer

  • Native To

    North America

Growing Conditions

  • Soil pH

    Acidic, Neutral, Alkaline

  • Soil Drainage

    Well Drained

  • Soil type

    Loam, Sand

  • Tolerances

    Drought

  • Growth Rate

    Medium

  • Water Requirements

    Average Water

  • Habit

    Upright/Erect

  • Seasonal Interest

    Spring, Summer

Ornamental Features

  • Flower Interest

    Showy

  • Flower Color

    White, Pink

  • Fruit Color

    Yellow Green, Tan

  • Foliage Color (Spring)

    Green

  • Foliage Color (Summer)

    Green

  • Fragrant Flowers

    No

  • Fragrant Fruit

    No

  • Fragrant Foliage

    No

  • Bark or Stem Fragrant

    No

  • Flower Petal Number

    Single

  • Repeat Bloomer

    Yes

  • Showy Fruit

    No

  • Edible Fruit

    No

  • Showy Foliage

    No

  • Foliage Texture

    Fine

  • Foliage Sheen

    Matte

  • Evergreen

    No

  • Showy Bark

    No

Special Characteristics

  • Usage

    Cutflower, Mixed Border, Rock Garden / Wall, Wildflower

  • Sharp or Has Thorns

    No

  • Invasive

    Sometimes

  • Attracts

    Butterflies

  • Self-Sowing

    Yes