Circle Onion (Allium senescens var. glaucum): Swirling Blue Foliage and Lollipop Blooms

Overview

Allium senescens var. glaucum, known as circle onion or curly onion, is a distinctive variety celebrated for its intensely blue-gray, swirling foliage that forms a cowlick-like mound. Its lollipop-shaped flower heads—pink with bright yellow centers—add whimsical charm in late summer.

Botanical Description

Foliage forms a dense, swirling mound 20–30 cm tall and wide of narrow, blue-gray leaves that twist in a spiral pattern. Flower stems rise to 40–50 cm, topped with spherical umbels 3–4 cm wide of pink florets with conspicuous yellow anthers, creating a two-tone "lollipop" effect. Blooms late summer to early fall.

Taxonomy

Genus:	Allium
Species:	senescens var. glaucum

Growing Conditions

• Light: Full sun to part shade.
• Soil: Average to dry, well-drained.
• Moisture: Dry to medium; drought-tolerant.
• Hardiness: USDA zones 4–8.

Care and Maintenance

Divide regularly to maintain vigor. Divide plants any time during growing season by separating bulbs, ensuring a rhizome piece attaches to each. Deadhead to prevent seeding.

Propagation

Flowers in two years from seed. Sow seed in situ or divide in spring. Division is faster and preserves the blue foliage trait.

Problems

Aphids, powdery mildew, rust occasionally. Good air circulation and drainage prevent most issues.

Garden Uses

Rock gardens, cottage gardens, dried flower arrangements, groundcover, border edging. The blue foliage provides season-long interest even out of bloom.

Quick Reference

Height:	30–90 cm
Spread:	15–30 cm
Growth Habit:	Clumps
Bloom Time:	Early Fall, Fall, Late Summer, Summer
Flower Color:	Pink, Yellow
Characteristics:	Attracts Butterflies, Fragrant Foliage