Scytheleaf Onion
Allium falcifolium
Care
full sun
moderate
Slow
Mar-Aug
Resistant
Friendly
Yes
Bulbs eaten raw or cooked; used like cultivated onions for flavoring
Serpentine areas of the North Coast Ranges from Mendocino County to Santa Clara County, 1000-3000 ft elevation.
Care Guide
Planting
Plant your scytheleaf onion in full sun with well-draining soil - it thrives in heavy, rocky soils and naturally grows in serpentine areas, so don't amend your soil to be too rich. The spring blooming season suggests planting in fall or early winter to establish before flowering. Space bulbs about 6 inches apart to allow room for the plant's modest spread.
After Planting
Water moderately during the growing season, then reduce watering as the plant heads into dormancy after flowering. Scytheleaf onion is deer resistant and requires minimal maintenance once established - no deadheading or pruning is needed. The biggest mistake Bay Area gardeners make is overwatering; this is a drought-tolerant native that actually prefers drier conditions, so err on the side of underwatering rather than keeping the soil consistently moist.
Endangered & Threatened Species Supported
Listed as Endangered under CESA
Wildlife Supported
Insects
Early season pollen source for queen establishment and colony founding
Spring larval host in montane/foothill populations; single generation annual cycle
Early spring caterpillar host; larvae develop on Allium foliage
Larval host plant; caterpillars feed on foliage during spring development
Birds
Spring foraging for emerging bulbs and foliage in grassland habitats