7 Irresistible Alliums for Your Garden

Ornamental onions (Allium) have a unique appearance and add shape and structure to your garden. Many varieties bloom early in the year. The striking, spherical flower clusters of ornamental onions come in shades of purple, lilac, pink, red, or white. Alliums are a great addition to any garden, whether you have a sleek, modern garden or a lush flower garden.

Not only are ornamental onions beautiful to look at, but they also attract many bees, butterflies, and insects. There are many different species and varieties—ranging from small, more natural-looking ornamental onions to enormous Allium bulbs, whose stems you’d hardly expect to support their weight. There’s also a lot of variety when it comes to flowering times. There are early-blooming ornamental onions that bloom in early spring, Allium varieties that bloom later in the spring, and even summer-blooming Alliums! Curious about the most beautiful Allium for your garden? Check out our Top 7 Alliums.

The 7 Most Beautiful Allium Species

1. Allium Globemaster

The largest, longest-blooming, and—according to many—the most beautiful Allium: Globemaster. This impressive ornamental onion grows to about 100 cm tall and produces spherical purple flowers. These flowers are about 10 cm at the start of blooming but grow to as much as 25 cm! It blooms for weeks and has sturdy stems. A stunning focal point for your garden.

Features

• Height: 90–100 cm
• Flower size: 20–25 cm
• Color: lilac, purple
• Flowering period: early May – June

2. Allium Mount Everest

Allium Mount Everest is a tall, large ornamental onion with white flowers. It grows to nearly a meter in height and has sturdy stems. It looks stunning planted in groups in modern and formal gardens, or as a contrast in a spring garden, or in a border with purple Alliums. It closely resembles Allium Mont Blanc, but grows slightly shorter.

Features

• Height: 90 cm
• Flower size: 15 cm
• Color: white
• Flowering period: early May – June

3. Allium Christophii

Allium Christophii is a unique Allium with an open flower form and an airy character, which makes its star-shaped flowers stand out even more. Its Dutch name is, in fact, “star garlic.” The flower color is dark purple with a silvery sheen, almost metallic in appearance. It remains attractive long after flowering and pairs beautifully with ornamental grasses such as Stipa. It is also sometimes referred to as Allium albopilosum.

Features

• Height: 60 cm
• Flower size: 15–20 cm
• Color: glossy lilac, purple
• Flowering period: June

4. Allium Miami

Allium Miami has a semicircular flower shape and is flattened at the base. The flowers are purplish-red and distinctly star-shaped. As flowering progresses, the flower shape becomes more open, and Miami closely resembles Allium schubertii. Its distinctive dark reddish-purple color comes from Allium atropurpureum. It makes a beautiful contrast with other ornamental alliums.

Features

• Height: 80 cm
• Flower size: 10–15 cm
• Color: purple, red
• Flowering period: late May – June

5. Allium Purple Sensation

Allium Purple Sensation is the classic Dutch Allium. This ornamental onion is planted very widely and is (as a result) available at a very affordable price (perfect for large quantities). It’s also very easy to grow and reliable. It practically always comes back, even in clay soil. Purple Sensation has a fairly large bulb shape, though it is slightly smaller than newer cultivars like Globemaster or the old giganteum. It retains its shape well.

Features

• Height: 80–90 cm
• Flower size: 10–12 cm
• Color: lilac, purple
• Flowering period: early May – June

6. Allium sphaerocephalon (round-headed onion)

Unlike many other ornamental onions, Allium sphaerocephalon has a more natural appearance. The flower is much smaller than most other Alliums. This pointed, oval-shaped ornamental onion attracts large numbers of bees and butterflies. Allium sphaerocephalon blooms from late spring through summer. The flower starts out green and gradually changes color from top to bottom to magenta. Ball garlic pairs beautifully with perennials and ornamental grasses and looks best when planted in larger groups. This Allium has several Dutch names: drumsticks, ball garlic, and chalk garlic.

Features

• Height: 60 cm
• Flower size: 5 cm
• Color: purplish red (green)
• Flowering period: June–July

7. Allium Summer Beauty

Allium Summer Beauty is a true summer-flowering Allium that blooms profusely from June through August or September, producing soft lilac-purple flowers. Bees and butterflies love it! It’s worth noting that the slender foliage of this (and many other summer-blooming) ornamental alliums remains attractive well into the fall. It pairs perfectly in the summer garden, for example with perennials and/or ornamental grasses. Preferably planted in large numbers. If you’d like a slightly darker (or shorter) variety, go for Allium Millennium.

Features

• Height: 50 cm
• Flower size: 5 cm
• Color: lilac-pink
• Flowering season: June–August

Allium Tips

Did you know that Allium is very easy to grow and requires little maintenance? Still, we’d like to share a few tips on planting and care:

• Keep in mind that Allium prefers well-drained soil. If the soil is too wet, the bulbs will rot and won't come up (again) next year.

• Most Allium species prefer a sunny spot in the garden. However, some also grow in partial shade, such as Purple Sensation.

• Plant Allium bulbs about 2–3 times as deep as the bulb is tall.

• When planting, keep in mind that large Allium varieties should not be planted too close together.

• Allium often develops unsightly foliage when it begins to bloom. The leaves turn yellow and lose their appeal. By planting attractive foliage plants around the Allium, this is no longer noticeable. Consider geraniums, ferns, or lady's mantle.

• Just leave the spent Allium blooms where they are! Many varieties retain their shape for weeks or even months.

• Did you know that there are also summer-blooming Alliums? For example, numbers 6 and 7 from our favorites: drumsticks and Allium Summer Beauty. Allium Millenium and Allium Summer Drummer also bloom in the summer. The latter, however, grows quite tall—up to about 180 cm!

The Most Beautiful Allium Combinations in the Border

Alliums pair very well in gardens and flower beds. Here are our tips for the most beautiful allium combinations in your garden.

Allium pairs well with flower bulbs that bloom a little later, such as (late) tulips. You can also create beautiful combinations with Allium and perennials. Think of early-blooming perennials, or perennials that already have attractive foliage while your Alliums are in bloom. Combining Allium with (evergreen) ornamental grasses is also recommended. Summer-blooming Allium varieties remain attractive even after the ornamental grasses have finished blooming.

Would you like to incorporate Allium into a natural garden? If so, consider choosing the "ball-shaped" variety, also known as drumsticks. These are true bee-friendly plants, and their shape is much less formal than that of many well-known ornamental onions.