Millenium Ornamental Onion: Rosy Globes After the Lavender Harvest

Millenium ornamental onion is one of the most dependable summer-blooming alliums, and it was named Perennial Plant of the Year in 2018. In late July and August it covers itself in 2-inch globes of bright rosy purple, held just above a neat clump of glossy, strappy leaves.

That timing is what makes it so useful in a lavender garden. Just as the main lavender harvest is cut and bundled, Millenium picks up the purple and keeps it going.

Millenium at a glance

Planning a purple relay

A lavender bed peaks hard in early summer and then goes quiet once you harvest. Millenium is short enough to stand in front of lavender without hiding it, and its round heads contrast nicely with lavender's narrow spikes. Plant it in groups of three to five along the front edge, or tuck clumps between lavender plants where they will not crowd the lavender's base.

Unlike spring alliums that grow from bulbs and leave yellowing leaves behind, Millenium grows from a compact clump with foliage that stays attractive all season. That matters in a bed you look at every day. Line up bloom times in the Companion Plant Planner.

Planting and care

• Planting: set the bare root clump with its crown at soil level, water well and keep it lightly moist until new growth appears.
• Soil: lean to average and well drained, just like lavender.
• Water: regular watering the first summer, then only in long dry spells.
• Cleanup: trim any tired foliage in fall or early spring.
• Dividing: lift and split the clump in spring every few years to keep it vigorous or to spread it along the bed.

For pollinators and the vase

At peak bloom Millenium is crowded with bees and butterflies, which suits a lavender garden that is already a pollinator magnet. The globes also cut well for small arrangements, and the faded heads stay attractive in the garden if you leave them. Brushing the leaves releases a mild oniony scent, but this is an ornamental, not a kitchen allium.

Frequently asked questions

Will Millenium spread all over the garden?

It forms a compact, upright clump that widens slowly. Dividing every few years keeps it in bounds.

Does it need full sun?

It blooms best in full sun and tolerates part shade. Next to lavender it will get all the sun it wants.

Do deer bother it?

Deer and rabbits tend to leave it alone, which makes it a reliable choice for open rural gardens.

Keep exploring

• Millenium Ornamental Onion Bare Root Plant
• Companion Plant Library
• Companion Plant Planner
• Beekeeper Tools