Allium cristophii aka Persian Onion

Allium cristophii, or star of Persia, is a bulbous perennial. It belongs to the Amaryllidaceae family. Its native range includes Turkey, Turkmenistan and northeastern Iran. Garden plants grow about 1–2 feet [0.3–0.61 metres] tall. Some recorded plants stand just 0.5 feet [0.15 metres] high. Clumps spread about 1–2 feet [0.3–0.61 metres] wide. The bulbs form dense groups that spread slowly over time.

Flat, strap-shaped leaves grow from the base in early spring. They reach about 1.7 feet [0.51 metres] in length. Their green to gray-green surface has a slight blue cast. Bruised leaves give off an onion or garlic scent. The leaves start to fade before the flowers open. Smooth, round, green stems rise above the dying leaves. These bare stems hold large, round umbels of star-shaped flowers.

Flowers open from late spring into early summer. In St. Louis, bloom falls in May. Each head can hold up to 100 small flowers. The six-petalled blooms range from pale lavender to rosy violet. They can have a silvery or metallic sheen. Flower heads span about 0.7–1 foot [0.2–0.3 metres]. Capsules follow the flowers and contain black seeds. The dry heads add interest after bloom ends. Butterflies, other pollinators and songbirds visit the plants.

Grow this bulb in full sun and fertile, well-drained soil. Sandy or gritty loam suits it well. It accepts acid, neutral and alkaline soils. Give it moisture while it grows, but avoid soggy ground. Established plants tolerate drought, including dry summer conditions. Containers suit gardens with heavy clay that stays wet in winter. Plant bulbs in fall and divide established clumps then. It needs little care beyond removing spent stems and leaves. Sources rate it for USDA zones 4–8 and UK H5.

Use it in borders, rock gardens, meadows or containers. Its flowers suit both fresh and dried arrangements. Deer and rabbits tend to leave it alone. Self-seeding can cause unwanted spread, though it is not considered invasive. Remove fading flower heads to limit seed production. Wet soil can cause bulb rot. Other possible problems include mildew, rust, leaf spots and thrips. Leaf miner, onion fly and white rot may also occur. NC State lists bulbs and stems as edible, raw or cooked. Yet it also flags poisoning risks for people, cats and dogs. Eating the plant may cause nausea, vomiting or diarrhea.