Data provided by the participants of the Consortium of California Herbaria

View additional distribution information on the Jepson eflora

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.

Plant type

Perennial herb, Geophyte

Size

1 - 3 ft Tall
1 in Wide

Form

Upright Columnar

Growth rate

Slow

Dormancy

Summer Deciduous

Fragrance

Slight

Calscape icon
Color

Lavender, Pink, Yellow, White, Purple

Flowering season

Spring

Special uses

Containers, Deer resistant

Sun

Deep Shade, Partial Shade

Water

Moderate

Summer irrigation

Never irrigate once established

Ease of care

Easy

Cold tolerance

Tolerates cold to 10° F

Soil drainage

Slow

Soil description

Prefers heavy soils but tolerates a variety of garden soils. Tolerates serpentine soils.
Soil PH: 7.0 - 9.0

Sunset Zones

4, 5, 6, 7*, 8, 9*, 14*, 15*, 16*, 17*, 18, 19*, 20*, 21*, 22*, 23*, 24*

Site type

Pockets of grassland within forest or chaparral, or grassy streambanks with moist clay soils, in the Coast Ranges and foothills

Plant communities

Chaparral, Montane Chaparral

Bees
Caterpillars
Butterflies

Butterflies and moths supported

0 confirmed and 16 likely

Confirmed Likely

Ipsilon Dart

Agrotis ipsilon

The Nutmeg

Anarta trifolii

Alfalfa Looper Moth

Autographa californica