10 Types of Purple Allium Flowers

Giant onion plants with tall thin stems and circular heads of small purple flowers

The Spruce / Evgeniya Vlasova

There are many hundreds of species in the Allium genus, including the vegetables we know as onions, chives, and leeks. But there are many alliums that work well as ornamental plants, often known as "ornamental onions" or "flowering onions." These plants grow from bulbs, like spring tulips and daffodils, but alliums typically bloom a bit later than spring bulbs, beginning in late spring and flowering well into summer.

The appeal of alliums is not in the foliage, which tends to be rather sparse and grass-like, but in the colorful flower clusters that perch atop tall stalks. Usually roughly spherical in shape, these umbels of tiny star-shaped flowers appear as ethereal balls of color in the garden, magically floating above the other plants.

Grow ornamental onions in full sun and well-draining soil. They need an adequate amount of moisture consistently, but their bulbs don't like to be waterlogged. Since they perform better in fertile ground (they like nitrogen), mix plenty of compost into the soil. After blooming, let the foliage die back of its own accord, and remember to water the plants during this period. Purple allium flowers are deer-resistant and rabbit-proof. Even rodents leave them alone.

Here are 10 allium types of allium, in a wide range of purple hues, to consider for your garden.

Gardening Tip

In the case of alliums, the importance of using companion plants goes beyond color combinations. Since the leaves of flowering onions become less and less attractive as the season wears on, it's advisable to hide them. Companion plants can do just that. Use bigger companion plants to achieve this end when dealing with bigger alliums.


Another factor to consider when deciding upon suitable companions is plant texture. The coarse flower head of an allium such as 'Ambassador' will contrast nicely with the more delicate flowers of Six Hills Giant catmint, for example.

  • 01 of 10

    Ornamental Onion (Allium atropurpureum)

    Ornamental onion with burgundy flowers

    The Spruce / David Beaulieu

    While many purple alliums are hybrid plants, this is a pure species. Allium atropurpureum is perhaps the darkest purple allium. Its flowers have enough of a touch of red in them to be considered wine or maroon. Color is, in fact, the main draw in growing this type of flowering onion, as the blooms are small compared to many hybrid alliums. The size of the flower head, which forms not a full globe (sphere) but a half globe, is just 2.5 inches.

    • Native Area: Hungary, Turkey
    • USDA Growing Zones: 4–8
    • Height: 2–3 feet
    • Sun Exposure: Full sun
  • 02 of 10

    'Ambassador' (Allium 'Ambassador')

    'Ambassador' allium with purple blooms

    The Spruce / David Beaulieu

    'Ambassador' is a mauve-purple variety of purple allium. When the flower buds are still tight, the globe perched atop the sturdy stalk measures about 5.5 inches. But soon, the individual flower stems start to peel from the center, the buds fully open, and—lo and behold—the diameter of the flower head increases to an impressive 7 inches. 'Ambassador' is a hybrid of several native allium species.

    • Native Area: Nursery hybrid
    • USDA Growing Zones: 4–8
    • Height: 3–4 feet
    • Sun Exposure: Full sun
  • 03 of 10

    'Globemaster' (Allium 'Globemaster')

    'Globemaster' allium with purple blooms

    The Spruce / David Beaulieu

    With a name like 'Globemaster,' this hybrid allium clearly claims to be the poster child for the ornamental onions that display spherical flower heads. The fact that its flowers are densely packed, thus forming a tight ball, lends some credence to this claim because it gives the flower head the appearance (from a distance) of a solid ball, rather than a collection of smaller flowers, which it actually is. 'Globemaster' alliums should be their biggest in their first year, bearing heads 8 inches across. After that, they downsize, both in terms of heads and overall plant height.

    • Native Area: Nursery hybrid
    • USDA Growing Zones: 5–8
    • Height: 18–30 inches
    • Sun Exposure: Full sun
  • 04 of 10

    'Purple Sensation' (Allium hollandicum 'Purple Sensation')

    'Purple Sensation' alliums with dark purple blooms

    The Spruce / David Beaulieu

    If the name of 'Globemaster' suggests a plant with big ideas about its standing amongst alliums with globe-shaped flower heads, then 'Purple Sensation' would seem to bound and determined to be at the head of the class in terms of displaying a purple color. The deep purple flowers are about 4 inches across, blooming in May and June, before most of the large-flowering alliums.

    • Native Area: Iran, Kyrgyzstan 
    • USDA Growing Zones: 4–10
    • Height: 24–32 inches
    • Sun Exposure: Full sun
    Continue to 5 of 10 below.
  • 05 of 10

    Blue Allium (Allium careleum, Allium azureum)

    Blue alliums with blue petals

    The Spruce / David Beaulieu

    Two allium species carry the common name "blue allium": Allium caeruleum and Allium azureum. Both plants have relatively small, 1.5-inch flowers in a purplish-blue hue. They bloom in late spring and early summer, well before the large-flowering alliums.

    • Native Area: Central Asia
    • USDA Growing Zones: 4–10
    • Height: 14–20 inches
    • Sun Exposure: Full sun
  • 06 of 10

    Giant Onion (Allium giganteum)

    Giant onion plant with circular heads of purple flowers closeup

    The Spruce / Evgeniya Vlasova

    Although giganteum means "giant," this allium's moniker refers to plant height and not flower head diameter, which, averaging at 5 inches, is smaller than the heads of both 'Globemaster' and 'Ambassador' alliums.

    • Native Area: Central and western Asia
    • USDA Growing Zones: 5–8
    • Height: 3–5 feet
    • Sun Exposure: Full sun
  • 07 of 10

    Star of Persia (Allium cristophii)

    Star of Persia allium with pale lavender blooms
    Fotograf aus Leidenschaft / Getty Images

    Allium cristophii, also known as Star of Persia, produces large spheres of tiny pale-lavender flowers that resemble exploding fireworks. The flowers heads are among the largest of all alliums, at up to 12 inches in diameter. The blooms hold their shape well, often lasting in midsummer.

    • Native Area: Iran, Turkey, central Asia
    • USDA Growing Zones: 4–8
    • Height: 1–2 feet
    • Sun Exposure: Full sun
  • 08 of 10

    Tumbleweed Onion (Allium schubertii)

    Tumbleweed allium with pink blooms

    The Spruce / David Beaulieu

    It's a reach to call the tumbleweed onion a purple allium, since the small flowers are more accurately described as pink, but the attraction is the size and shape of the flower head—not its color. The irregular shape of the 18-inch head gives it the appearance of fireworks that have just exploded. It shares this quality with A. cristophii.

    • Native Area: Eastern Mediterranean, central Asia
    • USDA Growing Zones: 5–8
    • Height: 1–2 feet
    • Sun Exposure: Full sun
    Continue to 9 of 10 below.
  • 09 of 10

    'Early Emperor' (Allium 'Early Emperor')

    'Early Emperor' allium with purple flowers
    Hana Richterova / Getty Images

    The 'Early Emperor' allium has a somewhat looser flower head of rich purple flowers with bright white stamens that appear in May, before most of the other tall alliums, hence its name.

    • Native Area: Nursery hybrid
    • USDA Growing Zones: 5–7
    • Height: 2–4 feet
    • Sun Exposure: Full sun
  • 10 of 10

    'Gladiator' (Allium 'Gladiator')

    'Gladiator' allium with lavender flowers
    anutr tosirikul / Getty Images

    'Gladiator' is among the most statuesque of the purple-flowering hybrid alliums, with sturdy 3-to-4-foot stalks supporting 6-inch flower heads that are densely packed with tiny star-shaped flowers. This award-winning plant blooms in late spring and early summer.

    • Native Area: Nursery hybrid
    • USDA Growing Zones: 3–8
    • Height: 3–4 feet
    • Sun Exposure: Full sun