Millenium is one of the most dependable summer-blooming ornamental onions, named Perennial Plant of the Year in 2018. In late July and August it produces a profusion of 2-inch, bright rosy purple globes on strong stems just above the foliage.
The glossy green, strappy leaves form a compact, upright clump that stays attractive all season. At 15 to 20 inches tall, it is perfect for the front of a border, rock gardens and containers. Butterflies and bees love it, deer and rabbits do not, and it shrugs off drought once established.
What it looks like
Tightly rounded flower heads about 2 inches across packed with many small starry florets in bright rosy purple, held on strong, straight green stems just above the leaves. Leaves are glossy, medium green, thick and strap-like, forming a neat, upright tuft. The plant is 15 to 20 inches tall and 10 to 15 inches wide. At peak bloom it is crowded with rosy purple balls, often busy with bees and butterflies.
Growing it with lavender
Millenium thrives in the same full sun and lean, well-drained soil as lavender, and its rosy purple globes carry purple color through late summer at the front of a lavender bed.
Care
Grow in full sun to part shade in lean to average, well-drained soil; it handles drought once established. Hardy in USDA zones 4-8. Trim off any tired foliage in fall or early spring; clumps can be divided in spring every few years.
At a glance
-
Botanical name: Allium
-
Flower color: Bright rosy purple
-
Foliage: Glossy medium green
-
Growth habit: Compact, upright clump
-
Mature size: 15–20 in tall × 10–15 in wide
-
USDA hardiness zones: 4–8
-
Light: full sun, part sun to part shade
-
Bloom start: Late-July
-
Peak bloom: Early-August
-
Bloom pattern: Single Flush
-
Deer resistance: Resistant
-
Pollinator value: Excellent
Sizes and shipping
Dormant bare-root plant, sold in boxes of 25 per variety (order in multiples of 25). Bare-root plants ship or are picked up March 1–May 31 only. They are soil-free, so they may ship to every state in that window. Dormant plants often show little or no top growth on arrival; plant or heel them in promptly.