Alliums, also known as ornamental onions, bring striking color and structure to the garden. With their globe-shaped flower heads in shades of purple, white, and pink, they are a favorite for both modern and classic borders. Here, we introduce some of the most popular Allium varieties, explain their differences, and help you choose the right type for your garden.

Well-Known Allium Varieties

• Allium 'Purple Sensation': One of the most popular choices, with medium-sized, deep purple flower heads on stems about 80-90 cm tall. Flowers in late spring to early summer.
• Allium 'Globemaster': Known for its very large, dense purple flower heads (up to 20 cm across) on sturdy stems around 80-100 cm. Blooms slightly later than 'Purple Sensation'.
• Allium 'Mount Everest': A striking white-flowered variety, reaching 100-120 cm in height. Its spherical blooms add brightness and contrast to mixed borders.
• Allium sphaerocephalon (Drumstick Allium): Compact, egg-shaped flower heads that start green and mature to reddish-purple. Grows to about 60 cm and blooms in early summer.
• Allium christophii (Star of Persia): Large, airy flower heads with star-shaped lilac flowers, up to 20-25 cm wide, on shorter stems (40-50 cm). Excellent for naturalistic plantings.
• Allium 'Millenium': A lower-growing, clump-forming variety with pinkish-purple blooms in mid to late summer. Suitable for borders and pots.

Differences in Height, Color, and Flowering Time

Alliums offer a wide range of heights, from compact types suitable for pots or front borders (like 'Millenium' or Allium moly) to tall, architectural varieties such as 'Globemaster' and 'Mount Everest'. Flower head size and color also vary: most are purple, but white and pink cultivars are available. Flowering times range from late spring to mid-summer, so by mixing varieties, you can enjoy alliums in bloom for several months.

Alliums for Borders and Pots

Taller Alliums like 'Globemaster', 'Mount Everest', and 'Purple Sensation' are ideal for the middle or back of borders, where their upright stems rise above perennials and grasses. Compact types such as Allium sphaerocephalon, Allium moly, and 'Millenium' work well at the front of borders or in containers. When planting in pots, ensure good drainage and use a generous number of bulbs for a full effect.

Tips for Choosing the Right Allium

• Consider the height and color you want to add to your garden. Taller varieties make a bold statement, while smaller types are more subtle.
• Check the flowering period to extend the season of interest by combining early and late-blooming types.
• Mix different Allium species for varied shapes and textures, or plant in groups for a more uniform look.
• Alliums are generally hardy and return each year if planted in well-drained soil.