PL. —Eriogonum cinereumBotanical illustration — drop image
Eriogonum cinereum

Ashyleaf Buckwheat

SpringSummerFall
8a10bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Not in bloom
Summer
Peak bloom
Fall
Peak bloom
Peak bloom
In bloom
Background

Eriogonum cinereum is a mounding shrub native to coastal scrub in Southern California, occurring naturally from Santa Barbara to Los Angeles counties. Its woolly, gray-green leaves give the plant its common name, and dense clusters of small white to pale pink flowers appear from summer into fall, drawing native bees, butterflies, and beneficial wasps in large numbers.

Once established it requires little to no supplemental water and thrives in poor, sandy, or rocky soils with fast drainage. Heavy clay or regularly irrigated beds lead quickly to root rot and plant death. Light pruning after the main flowering period maintains a tidy mound and encourages fresh growth; cutting back into old leafless wood is best avoided. The plant handles coastal wind and light salt spray, making it well suited to exposed slopes and erosion-prone sites.

Eriogonum cinereum functions as a keystone plant in coastal sage scrub, providing nectar and pollen for dozens of native bee species and serving as a larval host for several native butterflies including the Acmon blue and Bernardino dotted-blue.

Care guide
SunFull sun
WaterLow
SoilWell-drained, sandy or gravelly, dry
Spacing4–6 ft
Height3–5 ft
Zone8a – 10b
Native RegionCA
Seasonal tasks
winter
cutAfter the main flush of flowering, shear or selectively cut back spent stems by up to one-third to tighten the mound shape. Do not cut into old bare wood.
spring
watchAfter winter rains, check the base of stems for blackening or soft tissue, which indicates phytophthora root rot triggered by standing water or overwatering.
cutRemove any dead or frost-damaged stems at their base before new growth begins in early spring.
summer
watchMonitor for native butterfly larvae, particularly blue butterflies using this plant as a larval host. Avoid any broad-spectrum insecticide applications during flowering.
fall
sowPlant container-grown stock in fall or early spring into fast-draining soil. On flat sites, build up a slight mound or amend with coarse grit to ensure water moves away from the crown.
Common problems

Phytophthora Root Rot

Symptoms

Wilting despite moist soil, yellowing leaves, stunted growth, and dark, decayed roots and crown tissue. Vines may collapse during hot weather.

Treatment

Plant in well-draining soil and avoid waterlogging. Remove and destroy affected vines. Improve drainage with raised beds or amended soil and avoid overwatering.