The ornamental allium is a stunning spring-flowering bulb grown for its mesmerizing, globe-shaped flowering heads.  Alliums are reliable and long-lasting perennials that return year after year, offering a dazzling display and a buzzing hub for pollinators. 

The allium is an inedible member of the onion family, but these ornamentals are a far cry from their odiferous cousins, as they are prized for their large ornamental flower heads.  

 

Why Should I Plant Alliums? 

They are tough! Native to Central Asia, this diverse group can typically be found growing wild in a range of intense habitats marked by hot dry summers, cold winters, and rocky, porous soil. The plants’ rugged nature is just one reason it has found a place in garden design over the centuries.  

They are diverse! This splendid plant family contains dozens of varieties that range in size, color, form, and height. There are small drumstick heads as well as mammoth varieties that stand tall with ponderous purple globes.  

Critters hate them! Globe alliums are resistant to deer and other small mammals, because these otherwise voracious vermin are turned off by the bulbs’ pungency. Thankfully humans can’t detect the oniony smell without crushing the plant.  

But pollinators love them! The large purple heads are comprised of countless small individual flowers to create a massive, nectar-rich cluster. These heads are always abuzz with a mix of beneficial insects from butterflies to bees.  

They have staying power! Whether you plant globe alliums in the landscape or the cutting garden, you will surely appreciate the long-lasting flower heads. Allow the alien-looking blooms to dry for a stunning everlasting. A small patch of globe alliums is a great investment, because they linger in the landscape and will return spring after spring for many years.  

Alliums are largely overlooked as garden superstars, and we think that needs to change!

 
 
How Do I Grow Alliums? 
 

Thanks to its rugged natural habitat, the globe allium is exceptionally easy to grow, but do keep these things in mind: 

Plant in fall. Allium bulbs require a cold winter in order to flower properly. The bulbs can be grown reliably in USDA zones 3-8; these regions have enough cool weather to signal the bulbs to sprout in spring. Alliums are native to places with intense hot and cold weather, so they are quite resilient to temperature extremes.  

Keep Things Loose. Because they will rot over winter in soggy soil, alliums need loose, well-drained soil. If you have clay-heavy or poorly draining soil, plant alliums in containers or raised beds and generously amend with well-rotted compost. It should include plenty of large-sized particles, such as sand or grit, to improve drainage. 

Do Some Math. Allium bulbs range in size depending on variety. A good rule of thumb is to plant the bulb 3 times deeper than its diameter; very large bulbs will be planted much deeper than drumstick types. Spacing will also vary depending on size; bulbs can generally be planted in clusters, spacing them no closer than 4 inches apart. 

Keep Things Sunny. Plant in full sun for optimal growing (though southern gardeners may want to provide a bit of afternoon or dappled shade). The bulbs have average water needs and can become quite drought tolerant once established.  

Leave, Cut, Dig. These magnificent heads generally unfurl in late spring to early summer and bloom for about 3 weeks. The heads will dry beautifully on the plant and can be left to feed wildlife, or you can harvest them for everlasting bouquets.  The bulbs will perennialize in the garden and live for many years. To keep the plants thriving, we recommend digging and dividing the bulbs 3 to 4 years after planting.  

 
Which Varieties Do You Recommend? 

Here are some of our favorite varieties: 

 

 Giganteum Allium: Perennial in zones 3-9. Gorgeous, gargantuan globes in the color of purple grapes! The globes of this largest-headed allium average 6 to 10 inches wide and grow atop stems from 3 to 5 feet tall. They are deer resistant and irresistible to pollinators. Giganteum is a favorite for cottage gardens, landscaping, beds, and borders. 

 

 Schubertii Allium: Allium schubertii (also known as Tumbleweed allium) Perennial in zones 4-10. These beautifully unusual alliums set off a blazing firework display in the garden! Stems reach just under 2 feet with heads 12 inches across. Unlike other alliums, the heads are not compact and tidy but rather consist of an explosion of thin flowers that give them a fascinating look.  
 

Globemaster Allium: Perennial in zones 3-9. This colossal globe allium is believed to be the largest variety! The extra-large lavender heads grow 8 to 10 inches across on 32-inch stems. These long-lasting blooms are super attractive to a range of pollinators and are a charming addition to the garden.