Robinson's onion (Allium robinsonii) is a rare, small bulbous species from the sandy and gravelly banks of the lower Columbia River, sometimes called the Columbia River onion. It grows well in cultivation when given very free-draining soil, full sun and a dry summer rest.
Family
Amaryllidaceae (Daffodil & onion family)
Grows as
Bulb
Light
Full sun
Water
Water moderately in the growing season and keep almost dry while dormant in summer.
Soil
Very sandy or gritty, free-draining mix.
Temperature
Hardy in cool temperate climates; protect from prolonged waterlogged cold.
How easy
Moderate
Edible
Yes, some parts
Native range
Washington to N. Oregon
Climate
temperate
About
Allium robinsonii, the Columbia River onion or Robinson's onion, is a rare plant species native to the US States of Washington and Oregon, although some studies suggest that the Oregon populations may now be extinct. The species has been reported from five counties in Washington (Ferry, Yakima, Grant, Franklin and Benton) and five in Oregon (Umatilla, Morrow, Gilliam, Sherman and Wasco). It is found in sand and gravel deposits along the lower Columbia River and some of its tributaries, usually at elevations less than 200 m. The species is also cultivated as an ornamental in other regions, including in Europe.
Allium robinsonii produces 1–3 egg-shaped bulbs up to 2 cm long, but no underground rhizomes. The flowering stalks are relatively short for the genus, rarely more than 8 cm tall.
Text excerpted from the Wikipedia article Allium robinsonii 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.