Plant of the Month for October 2012

Allium thunbergii; photo by Todd Boland
Allium thunbergii

Description and general information

This late-flowering ornamental onion is native to eastern China, Taiwan, North Korea and Japan. In the wild, it inhabits pastures and grassy slopes from sea level to 1300 m.

Plants form a grassy-clump of wiry leaves. Flowers stems arise 15-30 cm and are topped with a globular cluster of reddish-purple flowers with yellow-orange exerted stamens. This species is among the latest to bloom, with flowers from September to November. The flowers are surprisingly frost-resistant. Ozawa is the most popular clone but a white form and a dwarf form also exist.


Full sun is best but this Allium will tolerate part shade. The soil should be well-drained but not too dry. It is not particular about soil pH.

Bloom period

September to November


seed or division


sow seed at 4 C for 3 weeks then germinate at 20 C.


mature clumps may be divided in spring as the new foliage emerges.


not applicable

Plant Details Page: