Plant Finder

    perennial

    Giant Onion

    Allium giganteum

    Add To My Wish List

    print page
     
    Giant Onion (Allium giganteum) at Dutch Growers Garden Centre

    Giant Onion flowers

    Giant Onion flowers

    (Photo courtesy of NetPS Plant Finder)

    Giant Onion (Allium giganteum) at Dutch Growers Garden Centre

    Giant Onion in bloom

    Giant Onion in bloom

    (Photo courtesy of NetPS Plant Finder)

    Plant Height:  12 inches

    Flower Height:  4 feet

    Spread:  12 inches

    Sunlight:  full sun 

    Hardiness Zone:  4a

    Other Names:  Flowering Onion

    Ornamental Features

    Giant Onion features bold balls of lightly-scented purple flowers at the ends of the stems from early to mid summer. The flowers are excellent for cutting. Its sword-like leaves remain green in colour throughout the season. The fruit is not ornamentally significant.

    Landscape Attributes

    Giant Onion is an open herbaceous perennial with tall flower stalks held atop a low mound of foliage. Its relatively coarse texture can be used to stand it apart from other garden plants with finer foliage.

    This is a relatively low maintenance plant, and should only be pruned after flowering to avoid removing any of the current season's flowers. It is a good choice for attracting butterflies to your yard, but is not particularly attractive to deer who tend to leave it alone in favor of tastier treats. It has no significant negative characteristics.

    Giant Onion is recommended for the following landscape applications;

    • Vertical Accent
    • General Garden Use

    Planting & Growing

    Giant Onion will grow to be about 12 inches tall at maturity extending to 4 feet tall with the flowers, with a spread of 12 inches. It grows at a medium rate, and under ideal conditions can be expected to live for approximately 8 years. As this plant tends to go dormant in summer, it is best interplanted with late-season bloomers to hide the dying foliage.

    This plant should only be grown in full sunlight. It does best in average to evenly moist conditions, but will not tolerate standing water. It is not particular as to soil type or pH, and is able to handle environmental salt. It is highly tolerant of urban pollution and will even thrive in inner city environments. This species is not originally from North America. It can be propagated by multiplication of the underground bulbs.

    At Dutch Growers, we treat this plant as a "HOBBY PLANT". It is not officially recognized as winter-hardy in our zone 3, however, there is a strong liklihood that it will survive winter. Warranty expires on Nov. 1 season of purchase.

     
     
    Hardiness Zone Plant Height Minimum Sunlight
    Characteristics
    Articulation  Garden 
    Applications
    Flowers  Texture  Plant Form  Attracts Wildlife 
    Ornamental Features

    Search our store