Allium caeruleum Bulbs – True Blue Siberian Native, Persian Blue Globe, Deer Resistant, Fall Planting

Allium caeruleum — also known as Allium azureum or Persian Blue — is one of the rare true-blue flowers in the ornamental bulb world, producing stunning 1½-inch round globe flower heads composed of hundreds of tiny star-shaped pure flax-blue florets that create a dazzling, jewel-like effect in early summer borders. Native to Siberia and prized for its clear, intense blue — a color that pairs magnificently with silver-foliaged plants, creamy whites, and warm yellows — Caeruleum is a must-have for color-conscious gardeners seeking a cool, rich blue to anchor mixed perennial plantings. Deer resistant, easy to grow, and one of the most affordable alliums for large-scale naturalized plantings.

Why Gardeners Love It

• Rare true-blue globe flowers — one of the most genuinely blue ornamental alliums available
• 1½-inch round heads of hundreds of star-shaped flax-blue florets
• Siberian native — exceptionally cold-hardy and easy to establish
• Pairs beautifully with silver foliage, white flowers, and warm yellows
• Deer resistant and a magnet for bees and butterflies
• One of the most affordable large alliums for mass planting

Growing Details

• Type: Ornamental Allium
• Bloom color: True flax-blue (Persian Blue)
• Bloom time: Late spring to early summer
• Sunlight: Full sun to part shade
• Soil: Well-drained
• USDA Hardiness Zones: 4–8
• Planting depth: 2× bulb height
• Spacing: 5–6 inches apart
• When to plant: Fall

Planting & Care

Plant bulbs pointed tip up in well-drained soil in fall. Fertilize with bulb food at planting. Water well after planting. Thrive in full sun or partial shade with good drainage. Allow foliage to die back naturally after blooming. Combine with hostas, perennials, and ornamental grasses for a stunning layered display. Returns reliably year after year.