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COLCHICUM giganteum

Image of Colchicum giganteum

Jessie Keith

Family

Liliaceae

Botanical Name

COLCHICUM giganteum

Plant Common Name

Giant Autumn Crocus

General Description

Prized for its rosy-purple flowers that appear in late summer and early fall rather than in spring like those of most other "bulbs," this hardy perennial is native to northern Turkey. It has been known in gardens since the late nineteenth century. Although sometimes called "autumn crocus," it is not related to the genus Crocus, which is in the iris family.

This plant produces large broad strap-shaped leaves in spring, which gather energy for the underground bulb-like storage organ, known as a corm. In late summer, some 3 months after the leaves have withered, one to three funnel-shaped flowers arise on white, ankle-high, stalk-like floral tubes. Appearing about midway through the colchicum season, the blooms have six oval petal-like segments. They open wide in bright sun to display the orange-yellow anthers and a white eye. The large broadly conical corms may double or even triple in number each year, eventually forming a large clump that provides a spectacular fall show.

Colchicums do best in full to partial sun and deep, moist, fertile, well-drained soil. The corms are often planted under low groundcovers like creeping juniper or ivy, which provide a green background and support the blossoms during wind and rainfall. This lovely perennial also is perfect for bringing new life to the late-season perennial garden or shrub planting. It works well in meadows and flowering lawns. The corm will bloom even if not in soil! Purchase the corms in mid- to late summer, so they can be planted before they bloom.

All parts of Colchicum contain the potent alkaloid colchicine; see http://www.ces.ncsu.edu/depts/hort/consumer/poison/Colchau.htm

Characteristics

  • AHS Heat Zone

    9 - 1

  • USDA Hardiness Zone

    5 - 9

  • Sunset Zone

    2a, 2b, 3a, 3b, 4, 5, 6, 7, 8, 9, 10, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24

  • Plant Type

    Bulb or Corm or Tuber

  • Sun Exposure

    Full Sun, Partial Sun

  • Height

    4"-6" / 10.2cm - 15.2cm

  • Width

    5"-10" / 12.7cm - 25.4cm

  • Bloom Time

    Early Spring, Late Summer, Early Fall, Fall, Late Fall, Winter, Late Winter

  • Native To

    Europe, Turkey, Central Asia, Western Asia

Growing Conditions

  • Soil pH

    Acidic, Neutral

  • Soil Drainage

    Well Drained

  • Soil type

    Loam

  • Tolerances

    Drought

  • Growth Rate

    Medium

  • Water Requirements

    Average Water

  • Habit

    Clump-Forming

  • Seasonal Interest

    Spring, Fall, Winter

Ornamental Features

  • Flower Interest

    Showy

  • Flower Color

    White, Yellow, Purple, Violet

  • Foliage Color (Spring)

    Green

  • Foliage Color (Winter)

    Green

  • Fragrant Flowers

    Yes

  • Fragrant Fruit

    No

  • Fragrant Foliage

    No

  • Bark or Stem Fragrant

    No

  • Flower Petal Number

    Single, Double

  • Repeat Bloomer

    No

  • Showy Fruit

    No

  • Edible Fruit

    No

  • Showy Foliage

    Yes

  • Foliage Texture

    Coarse

  • Foliage Sheen

    Glossy

  • Evergreen

    No

  • Showy Bark

    No

Special Characteristics

  • Usage

    Alpine, Container, Cutflower, Foundation, Lawns and Turf, Mixed Border, Rock Garden / Wall, Wildflower

  • Sharp or Has Thorns

    No

  • Invasive

    No

  • Self-Sowing

    No