Allium Nigrum Bulbs for Planting - Snow White Ornamental Onion

Elegant White Blooms That Return Year After Year

Allium Nigrum is one of the most refined and underappreciated ornamental onions you can grow. Its softball-sized, silvery grayish-white flower heads are nearly flat-topped with distinctive green midveins — a subtle, architectural beauty that pairs effortlessly with peonies, Siberian iris, and early summer perennials. A reliable repeat bloomer that has graced gardens for decades.

Plant Highlights

• Genus: Allium (also known as multibulbosum)
• Bloom Color: Silvery white with green midveins
• Bloom Season: Early summer (June)
• Flower Size: Softball-sized, flat-topped umbels
• Mature Height: 24–30 inches
• Sun: Full sun to partial shade
• USDA Zones: 5–8
• Spacing: 5–6 inches apart
• Bulbs per sq. ft.: 4–5
• Soil Moisture: Average, well-draining

Why Grow Allium Nigrum?

• Deer, rabbit, vole, and rodent resistant
• Naturalizes and returns year after year
• Excellent fresh and dried cut flower
• Bridges the gap between spring and summer bloomers
• Slim vertical form fits even crowded border plantings

When to Plant

Plant bulbs in fall for late spring to early summer blooms. Like most ornamental alliums, Nigrum bridges the gap beautifully after tulips and daffodils fade and before summer perennials take over.

How to Plant

Choose a spot with full sun and well-draining soil. Plant bulbs with the pointed end up, about twice as deep as the bulb's height (typically 4–6 inches deep), spaced 5–6 inches apart. Water thoroughly after planting. Alliums are low-maintenance once established and will naturalize over time.

Care Tips

• Water about 1 inch per week during active growth
• Deadhead before seeds disperse to prevent self-seeding, or leave for naturalization
• Divide congested clumps right after flowering if needed
• Allow foliage to die back naturally to feed the bulb

Bulbs ship at the optimal time for fall planting in your region. Plant promptly upon arrival for best results.