San Diego Buckbrush

Ceanothus cyaneus

Native to:
Mexico, United States

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Rhamnaceae
Genus:
Ceanothus
Species:
Ceanothus cyaneus
USDA Symbol:
CECY

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Shrub
Height:
360 cm
Light Requirements:
Full Sun
Drought Tolerance:
High
Bloom Months:
apr,may,jun
Bloom Colors:
blue, violet
Landscaping Shrub:
Yes

Wildlife Benefits

Bees:
★☆☆☆☆ Documented bee visitation (GBIF)
Butterflies & Moths:
★☆☆☆☆ Documented Lepidoptera association (GBIF)
Caterpillars:
★☆☆☆☆ Recorded caterpillar host plant (HOSTS Database)

Keystone Species Ranking

Caterpillar Keystone:
★★★★☆ Butterfly & moth species supported by this genus (NWF)

Host Plant for Caterpillars

Periploca ceanothiella

Garden & Ecology Notes

Wildlife Value:
bees, butterflies, birds
Deer Resistant:
Yes
Fire Ecology:
Requires fire for germination
Fire Notes:
Seeds exhibit fire-stimulated germination; heat and smoke from fire break seed dormancy. Plants resprout from root crown after fire.

Soil Requirements

Soil Type:
rocky, well-drained, nutrient-poor soil
pH:
6.0 - 7.5 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
native to chaparral regions, prefers dry slopes

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–90 days
Scarification:
Seed coat scarification required before sowing
Germination Time:
14–60 days
Notes:
Hot water treatment or scarification followed by cold stratification improves germination. Smoke treatment may also enhance germination rates.

The above propagation data sourced from Claude AI

Pre-treatment: Cold-moist stratification for 30 days at 1–5°C (34–41°F).; then Scarify, then cold-moist stratify for 60 days.

Source: Claude AI