Oneleaf onion (Allium unifolium) is a bulbous wild onion from the coastal mountains of Oregon, California and Baja California, grown for its pink or white star-shaped spring flowers. It needs well-drained soil and a dry summer rest, and it has earned the RHS Award of Garden Merit.
Family
Amaryllidaceae (Daffodil & onion family)
Grows as
Bulb
Light
Full sun, Part shade
Water
Water through spring while leaves are growing, then keep dry in summer while it is dormant.
Soil
Free-draining soil; tolerates clay and serpentine.
Temperature
Hardy in cold winters; tolerates heat when dry in summer.
How easy
Easy
Edible
Yes, some parts
Native range
Oregon to W. California, Mexico (N. Baja California)
Climate
temperate
About
Allium unifolium, the one-leaf onion or American garlic, is a North American species of wild onion. It is native to the coastal mountain ranges of California, Oregon, and Baja California. It grows on clay soils including serpentine, at elevations up to 1100 m.
Allium unifolium, despite its name, usually has 2–3 flat leaves up to 50 cm long. Bulbs, though, are usually solitary, egg-shaped, up to 2 cm long, often formed at the end of rhizomes spreading out from the parent plant. Scapes are round in cross-section, up to 80 cm tall. Flowers are up to 15 mm across; tepals usually pink but occasionally white; anthers yellow or purple.
Text excerpted from the Wikipedia article Allium unifolium by its contributors, under CC BY-SA 4.0; the excerpts and the care summary drawn from them are shared under the same licence.
The care summary was written by AI (Claude, Anthropic) from the sources on this page, with general growing knowledge where they are silent. Check before relying on it.
Life form, climate and native range: World Checklist of Vascular Plants, Royal Botanic Gardens, Kew (CC BY 3.0), reformatted; see Plants of the World Online.