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ALLIUM

Image of Allium

Gerald L. Klingaman

Family

Liliaceae

Botanical Name

ALLIUM

Plant Common Name

Onion

General Description

This is an enormous and diverse plant genus. The onion family contains about 1250 species of herbaceous bulbous or rhizomatous plants that can be found across north temperate climates worldwide. All are perennials and cultivated forms are either grown for their ornamental flowers and foliage or as crops that yield edible greens and bulbs, such as onion, garlic, chive and leek. Species may be deciduous or evergreen and some are ephemeral.

Ornamental onions run the gamut from tiny groundcovers to enormous plants that produce large globe-like flowers. Most form uniform or spreading rosettes of foliage that can be thin and grassy or wide and strappy and dark green to blue-green. The flowers are small and star-like and appear in clusters of varying shapes and sizes that appear atop smooth leafless stems. The blooms come in many shades of white, yellow, pink, red, purple, and blue. Most of the flower heads are rounded and some, such as drumstick allium, are oblong.

Plant bulbous alliums as deep as they are tall; rhizomatous species should be planted with their rosettes at or just below the soil surface. Take care to plant alliums in well-drained, preferably sandy soil, since rot can result if too much moisture is held at the root zone. Once established, some alliums can tolerate drought. Reduce watering when the foliage begins to turn yellow.

With their wide range of bloom time, size and color, ornamental alliums are at home in spring bulb beds, mixed borders, containers and rock gardens.

Onions have a very distinctive oniony smell that’s derived from a variety of genus-specific chemicals, like cystein sulfoxide. These offer that oniony/garlicky taste and smell.

Characteristics

  • Plant Type

    Bulb or Corm or Tuber

  • Sun Exposure

    Full Sun, Partial Sun

  • Native To

    World/Pandemic, North America, Europe, Russia/Siberia, Northern Africa, Asia, India

Growing Conditions

  • Soil Drainage

    Well Drained

Ornamental Features

  • Flower Interest

    Showy

  • Fragrant Flowers

    Yes

  • Fragrant Fruit

    Yes

  • Fragrant Foliage

    Yes

  • Bark or Stem Fragrant

    Yes

  • Flower Petal Number

    Single

  • Showy Bark

    No

Special Characteristics

  • Sharp or Has Thorns

    No