Japanese onion is a wild onion from East Asia that blooms late in the season, with rounded clusters of red-violet flowers. In the United States it is a garden plant rather than a wild one, often grown as the cultivar 'Ozawa', which flowers in September and October. It is also called Thunberg's chive.
Appearance
- Appearance
- Narrow, hollow leaves that are triangular in cross section rise from small egg-shaped bulbs. Flower stalks reach about 1–2 ft (30–60 cm), topped by crowded clusters of small red to purple flowers with protruding stamens.
- Flowering time
- Late in the season, around September–October in Chicago-area gardens.
Look-alikes
Garlic chivesAllium tuberosum
Garlic chives have white flowers and flat leaves; Japanese onion has red-violet flowers and hollow, three-sided leaves.
Why they get mixed upBoth bloom in late summer to fall, and garlic chives grow wild in scattered places in several states, including Illinois, Michigan, and Ohio.
Where it lives
- Typical habitats
- mountain grasslands
- sunny slopes
- Range
- Native to Japan, Korea, China, and Taiwan. In the United States it is known as a garden plant, not a wild one.
- Preferred conditions
- Sunny mountain grasslands and slopes in its native range.
- Flowering
Flowers Sep–Oct
Flowers Sep–Oct
Growing it
- Care
- Hardy in USDA zones 4–9. Grow in full sun or part shade, and plant where earlier perennials won't shade it. Garden references list it as deer resistant.
Name and classification
- Varieties and forms
- 'Ozawa' is a cultivar grown in US gardens, with red-violet flowers. A white-flowered form also exists.
Conservation
- IUCN Red List
- DDData DeficientNot enough data yet to assess
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