Asphodelus fistulosus aka Wild Onion

Asphodelus fistulosus is a clump-forming perennial in the Asphodelaceae family. Its common names include onion weed and onion asphodel. Its native range spans Macaronesia and the Mediterranean to the Arabian Peninsula. It also includes Mauritius, and Kew classes its climate as subtropical. It is not native to Britain or Ireland. In the wild, it grows in dry, sandy or rocky places. These include fields, track edges and ground left uncultivated.

The plant forms tufts of narrow leaves that look like grass. Each leaf is rounded and hollow, reaching about 1 foot [0.3 metres] long. The foliage is deciduous, so it does not remain year-round. Hollow stems rise above the leaf clumps. The RHS describes plants around 2 feet [0.6 metres] tall. Its listed garden height range is 1.6–3.3 feet [0.5–1 metre]. Spread ranges from 0.3–1.6 feet [0.1–0.5 metres]. Plants take two to five years to reach full size.

The stems bear racemes of white or pale pink flowers. A reddish-brown line runs down the middle of each petal. Seed pods provide interest once the flowers have faded. Gardeners can leave the stems in place to show these pods. They can also cut the stems back after flowering. The plant suits flower beds, borders and informal cottage gardens. The RHS also lists it for gravel gardens and Mediterranean-style planting.

Grow it in full sun and soil with moderate fertility. Good drainage matters more than a narrow soil pH range. It accepts acid, neutral and alkaline conditions. The RHS lists chalk, loam and sand as suitable soils. Heavy soil that drains poorly can cause plants to die back. The supplied moisture range runs from dry to moist. The RHS gives it a UK hardiness rating of H4. Plants For A Future lists USDA zones 7–10. Propagation is by seed or division after flowering. The RHS reports few pest or disease problems. Plants For A Future flags some weed potential without grading its severity.

Plants For A Future lists leaves and roots as edible parts. It describes cooking the roots, though one account calls them fibrous. It also warns that reports of edible bulbs appear mistaken. The same source records traditional medicinal uses for the seeds. These include promoting urine flow and external use on inflamed skin. Such records do not establish safety or proven benefit. It lists no known hazards, but gives no specific pet-safety evidence.