Allium millenium

Allium ‘Millenium’ is a brilliant, modern ornamental onion that brings long-lasting colour and pollinator power to the summer garden. From mid to late summer it produces rounded, rose-purple flower heads held on strong, upright stems above neat clumps of glossy green foliage. Unlike some Alliums that flower and vanish, ‘Millenium’ forms a tidy perennial mound and looks good for months, making it perfect for borders, gravel gardens and patio containers. Bees and butterflies absolutely love it, and it’s also a great plant for adding structure and repeat interest when many spring-flowering bulbs have finished.

Planting Instructions

When to Plant:

Plant in spring, once the soil is warming and workable. Avoid planting during periods of hard frost or when the ground is waterlogged.

Where to Plant:
Choose a sunny position with well-drained soil. Allium ‘Millenium’ thrives in borders and is ideal for mixed borders, prairie-style planting, gravel gardens and containers. It’s drought tolerant once established and loves a warm, open spot.

How to Plant:

• Depth: Plant at the same depth as in the pot (or so the crown is level with the soil surface).
• Spacing: Space 30–40 cm (12–16 inches) apart to allow the clumps to thicken nicely.
• Soil Prep: In heavy soils, improve drainage by mixing in grit. Avoid very rich, over-fertile soil.

Watering:
Water well after planting and keep watered during dry spells in the first growing season. Once established, it needs only occasional watering during prolonged dry periods.

Aftercare Tips:

• Deadhead spent flower heads to keep plants tidy (or leave them for structure if you like the look).
• Remove old foliage in late winter/early spring as new growth starts.
• Divide clumps every 3–5 years in spring to maintain vigour.

Top Tip:
Allium ‘Millenium’ is a pollinator magnet—plant it near patios or paths so you can enjoy the bees at work. It also looks fantastic with ornamental grasses, Echinacea, Salvias and Nepeta.

Plant Details

Flowering Period:

July - September

Height:
14–20" (35–50cm)

Position:
Full sun

Hardy Perennial