Allium unifolium aka American Garlic

Allium unifolium is a small perennial that grows from bulbs. Common names include one-leaved onion and American onion. It belongs to the amaryllis family, Amaryllidaceae. Its native range runs from Oregon through western California. It also reaches northern Baja California in Mexico. It grows in a temperate climate. Wild plants occupy moist ground in California's coastal ranges. Habitats include pine woods and mixed evergreen forest.

Plants form compact clumps with short, grey-green leaves at the base. The leaves die back rather than stay green year-round. The RHS describes plants about 1 foot (0.3 metres) tall. Its broader height range reaches 1.6 feet (0.5 metres). Listed spread reaches about 0.3 feet (0.1 metres). Plants take two to five years to reach full size. In late spring, they bear pink-purple flowers shaped like stars. Each flower cluster, called an umbel, holds up to 20 blooms.

Grow this onion in full sun and fertile soil. Good drainage matters, even where the soil stays moist. The RHS lists chalk, loam, and sand as suitable soils. It favours soil with a neutral or alkaline pH. Choose a sheltered site facing south or west. Use containers where heavy clay stays waterlogged through winter. The RHS gives it a UK hardiness rating of H5. Chicago Botanic Garden lists USDA zones 5–7. These ratings describe hardiness under different regional growing conditions.

Its small size suits rock gardens, gravel beds, and pots. It also fits borders, cottage gardens, and wildlife gardens. Little pruning is needed beyond removing old stems and leaves. Sow seed when ripe or during spring. Another option is to lift bulbs after flowering ends. Carefully detach offsets to raise more plants. Watch for allium leaf miner and onion fly. Onion white rot and onion downy mildew may also occur.

Plants For A Future lists several edible parts. Bulbs and leaves may be eaten raw or cooked. Young shoots can be fried with the bulbs. The small bulbs measure about 0.03–0.05 feet (0.01–0.015 metres) across. Raw flowers can serve as a salad garnish. The same source reports plant juice as a moth repellent. It also records claims that whole plants deter insects and moles. It does not flag this species as weedy.