Although the Allium genus contains well-known food crops such as onions, garlic, and leeks, this group also contains stunning ornamental flowers. Most Allium flowers grow from bulbs and are generally hardy to USDA zones 4-8. They are perennials that will bloom beautifully year after year following a cold dormancy period.
Allium plants are native to mountainous and forested regions. They are accustomed to dry, hot summers and harsh winters, making them drought tolerant. These plants love the sun and require little to no watering during the summer months. They are relatively low-maintenance and pruning is only necessary to remove dried flower heads that may self-seed.
Flowers grow in clusters that may form a round flower head, they can also hang down gracefully. Allium plants come in a wide variety of colors including purple, white, pink, red, and yellow, making them perfect for adding a pop of color to any garden.
Although some Ornamental Alliums are edible, proceed with caution and always consult a medical professional, as they are simultaneously classified as being toxic.
The Most Beautiful Allium Varieties You Should Know
#1 Goliath (A. altissimum)
Unsurprisingly, “Goliath” is one of the tallest of the ornamental onions. These plants can stand up to four feet tall, and will surely steal the show with magnificent flower heads growing up to the size of a volleyball.
Individual flowers are star-shaped and a beautiful shade of violet pink. Flowers are fragrant and bloom from late spring to summer. Bear in mind during planting that these alliums will tower over the garden bed, so be sure to position them where they won’t obscure more discreet plants.
#2 Graceful Beauty (A. amplectens)
Allium amplectens, or Graceful Beauty is a delightful addition to any garden. It has pretty, white starry flowers which have lilac stamens and anthers. Blooms grow in clusters of 10-50 and form a round flower head up to 3 inches wide.
Plants grow up to 16 inches high and look best when planted in a group of at least 10 bulbs. Hardy to zones 4-8, they would make a lovely addition to a cottage-style garden and make beautiful cut flowers.
#3 Allium beesianum
Allium beesianum originated from China and is one of the few blue Allium species. It flowers from July to August, later than most Alliums. Growing up to 8 inches tall, foliage is grasslike and flowers are elongated, nodding bells hanging in clusters from the stalk end.
Blooms are a delicate purple-blue color reminiscent of Common Bluebells. Hardy to zones 6-9, this plant prefers well-drained soil and full sunlight.
#4 Keeled Garlic (A. carinatum subsp. pulchellum)
Keeled Garlic is a 1993 winner of the Award of Garden Merit from the Royal Horticultural Society. Originating from Romania, this Allium flower comes from woodland habitat so it can grow in partial shade and is hardy to zones 6-9.
Stalks rise 1.5 feet high with an informal spray of flowers dangling down. Flowers are small, slender, bell shapes and can be purple, pink or white.
#5 Lady’s Leek (A. cernuum)
Allium cernuum, also known as Lady’s Leek, is native to North America and hardy to zones 3-9. This plant forms clumps growing up to 18 inches high, with hanging, chandelier-like clusters of flowers.
Bell-shaped blooms are tiny and delicate with colors ranging from lilac to pink, to white. When cut or damaged, this Allium will give off an onion smell.
#6 Azure-flowered Garlic (A. caeruleum)
This Allium flower is a winner of the Award of Garden Merit from the Royal Horticultural Society. Growing up to 24 inches tall, flower heads are small and compact at only 1 inch wide. Clusters arise from narrow green stems and are made up of dozens of tiny, blue, star-shaped flowers.
These delicate plants are perfect for informal or cottage-style gardens, especially if planted in large sweeping drifts woven with bolder flowers such as pink Delphiniums. Azure-flowered Garlic naturalizes easily and is hardy to zones 4-10.
#7 Star Of Persia (A. christophii)
Star of Persia is a winner of the Award of Garden Merit from the Royal Horticultural Society. This is an elegant and unusual Allium, flower heads have narrow and spiky, star-shaped blooms which are a regal silver-purple color.
Standing up to 16 inches tall, flower heads can almost reach the size of a volleyball (8 inches wide). Stalks rise up from the low-lying foliage. Hardy to zones 5-8, this species will naturalize easily.
#8 Yellow-flowered Garlic (A. flavum)
Yellow-flowered Garlic is native to the Mediterranean and has beautiful, golden-yellow flowers which would look at home in a summer meadow. Each stem can produce up to 60 small, bell-shaped blooms which delicately hang down from thin, arching stalks.
This award-winning Allium (Award of Garden Merit from the Royal Horticultural Society), is extremely hardy with a USDA zone range of 4-10. Clump-forming, these plants grow up to 12 inches high and look very striking when grown in sweeping drifts.
#9 Giant Allium (A. giganteum)
The award-winning Giant Allium (Award of Garden Merit from the Royal Horticultural Society), is perhaps the tallest of all the Alliums, reaching heights of up to 6 feet tall. Flower heads can grow up to 6 inches wide and are made up of clusters of tiny, star-shaped, lilac-purple flowers.
These plants have long-lasting blooms and naturalize easily in zones 6-10. These dramatic flowers pair well with ornamental grasses which will highlight their beauty and impressive size.
#10 Purple Sensation (A. hollandicum)
Purple Sensation is not only an award-winning bloom (Award of Garden Merit from the Royal Horticultural Society) but is also a firm favorite among gardeners. This Allium plant is hardy to zones 4-9 and is prized for the rich, violet-pink color of its flowers.
Individual flowers are star-shaped, with dozens making up an eyecatching round flower head. Purple Sensation grows up to 3 feet tall and flower heads are up to 3 inches wide.
#11 Lombardy Garlic (A. insubricum)
Lombardy Garlic is a clump-forming Allium flower native to the Italian Alps. It is hardy to zones 4-9 and needs full sunlight and well-drained soil. This makes a beautiful border plant with its nodding, purple-pink flowers.
Clusters of bell-shaped flowers hang down from leafless stalks which can grow up to 20 inches tall. This plant will emit an onion and garlic scent if cut or damaged.
#12 Turkestan Onion (A. karataviense)
The Turkestan Onion is a show-stopping flower and has the Award of Garden Merit from the Royal Horticultural Society. This Allium variety is very suited for containers and blooms will last deep into the summer.
Even spent, dried flowers make for attractive home decor if arranged nicely in a vase. Round flowerheads grow up to 3 inches wide and consist of long-stalked starry blooms which are pale pink. Leaves are broad, curved, and a blue-green color.
#13 Lily Leek (A. moly)
Lily Leek, also known as Golden Garlic or Yellow Garlic, is an Allium native to Southern and southwestern Europe, hardy to zones 3-9. These are showy, sunshine-yellow, star-shaped flowers which can reach up to half an inch in size.
Flowers grow in loose clusters atop long stalks that can grow up to 15 inches tall. Leaves are flat and tulip-like and grow up to 12 inches long and up to 2 inches wide.
#14 Lopsided Onion (A. obliquum)
Allium obliquum, or the Lopsided Onion is named after its twisted stems which can reach up to 3 feet tall. Flowers heads are small and round and are made up of compact, star-shaped, yellow blooms.
These are herbaceous perennials and give off a strong onion or garlic scent if cut or bruised. They prefer sheltered spots with moist, well-drained soil.
#15 Mountain Lover (A. oreophilum)
Mountain Lover, also known as the Pink Lily Leek, is an Allium flower native to Eurasia. It has a short blooming period of 2-3 weeks which begins in May or June.
Flowers are a beautiful rosy pink and grow in loose clusters of 10-15 individual star-shaped blooms. Plants can grow up to 12 inches tall and will naturalize easily to form a colony.
#16 Rosy-flowered Garlic (A. roseum)
Rosy-flowered Garlic is a truly stunning flower, these delicate blooms would look perfect in a cottage garden border. They also do well in containers and love sun-filled spots. Plants grow up to 16 inches tall, with 3 inch wide flowers.
Flowers are fragranced and grow in clusters of star-shaped, pale to rich pink blooms. These flowers are long-lasting, and naturalize easily forming sweeping colonies. This Allium plant is hardy to zones 6-9.
#17 Tumbleweed Onion (A. schubertii)
Allium schubertii, or the Tumbleweed Onion, is an award-winning Allium flower (Award of Garden Merit from the Royal Horticultural Society). This plant is truly magnificent and is prized for its unique flowers.
Blooming in late spring to early summer, flowers grow in loose clusters which can only be described as looking like a firework or an explosion of stars. The flower head grows up to 12 inches wide with star-shaped, rose-purple blooms.
Once the flower head is spent and dried, it will detach from the stem and roll across the ground with the wind, dispersing its seeds. Hence the name, Tumbleweed Onion. The plant itself can grow up to 24 inches tall and will spread slowly over time, it is hardy to zones 4-10.
#18 Sicilian Honey Garlic (A. siculum)
Sometimes classified under the genus Nectaroscordum, Allium siculum is native to France, Italy, and Sicily, and is a Mediterranean Allium flower hardy to zones 5-10. A plant with truly lovely flowers, it grows up to 4 feet tall and would look fantastic in cottage-style gardens, Mediterranean-style gardens, and coastal gardens.
Flowers grow in groups of gracefully drooping bell-shaped blooms which are a delightful mixture of green, cream, and rich pink. This plant will give off the scent of garlic if it is cut or bruised.
#19 Oneleaf Onion (A. unifolium)
The Oneleaf Onion is an award-winning Allium (Award of Garden Merit from the Royal Horticultural Society), which grows in clusters reaching up to 24 inches tall. Each inflorescence contains up to 30 relatively large rose-pink, star-shaped flowers.
These delicate looking plants naturalize and spread freely. They can easily be grown in containers and attract butterflies, making them great for pollinator gardens or patios. They are hardy to zones 4-9, and prefer full sun and well-drained soil.
#20 Lebanon Onion (A. zebdanense)
Allium zebdanense, or the Lebanon Onion originates from Lebanon, Turkey, and Syria and is hardy to zones 5-9. It grows in dense clumps with grass-like foliage, and is great for the more shaded areas of the garden, although it can tolerate full sun.
This plant grows up to 3 feet tall and has groups of 3-10 large white flowers sitting on top of a leafless stalk. It is great for shaded borders, rock gardens or grown in containers.
Up next: How to Grow Alliums
Missouri Botanical Garden, Allium schubertii,
N.C. Cooperative Extension, Allium oreophilumI,
Pacific Bulb Society, Allium zebdanense,
Reinhard M. Fritsch. (2015). Checklist of ornamental Allium species and cultivars currently offered in the trade
Royal Horticultural Society, Allium oreophilum Mountain Lover,