San Bruno Mountain Manzanita
Arctostaphylos imbricata
- Native to:
- United States
John Game (www.wikidata.org)





Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Ericaceae
- Genus:
- Arctostaphylos
- Species:
- Arctostaphylos imbricata
- USDA Symbol:
- ARIM
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Shrub
- Height:
- 60 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- High
- Bloom Months:
- feb,mar,apr
- Bloom Colors:
- white, pink
- Ground Cover:
- Yes
- Evergreen Shrub:
- Yes
- Landscaping Shrub:
- Yes
Wildlife Benefits
- Bees:
- ★☆☆☆☆ Documented bee visitation (GBIF)
- Caterpillars:
- ★☆☆☆☆ Recorded caterpillar host plant (HOSTS Database)
Keystone Species Ranking
- Caterpillar Keystone:
- ★★★★☆ Butterfly & moth species supported by this genus (NWF)
- Pollen Specialist Bee Keystone:
- ★★☆☆☆ Native pollen specialist bee species supported by this genus (NWF)
Host Plant for Caterpillars
Epinotia arctostaphylana, Epinotia bigemina, orange tortrix moth (Argyrotaenia franciscana)
Garden & Ecology Notes
- Wildlife Value:
- birds, bees, small mammals
- Deer Resistant:
- Yes
- Fire Ecology:
- Fire adapted — tolerates or benefits from fire
- Fire Notes:
- Resprouts vigorously from basal burls after fire. Fire removes competing vegetation and stimulates flowering and fruiting in subsequent seasons.
Soil Requirements
- Soil Type:
- sandy, acidic, nutrient-poor soil
- pH:
- 5.5 - 7.0 (slightly acidic to neutral)
- Drainage:
- excellent drainage required
- Moisture:
- dry to moderate
- Notes:
- native to rocky, coastal chaparral habitats
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 60–90 days
- Scarification:
- Seed coat scarification required before sowing
- Germination Time:
- 30–90 days
- Notes:
- Seeds have hard seed coats requiring scarification or passage through animal digestive systems. Cold stratification improves 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
ORGHPS Germination Guide: Expose to fluctuation outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in the spring. Requires light or the seed is very fine. Surface sow and expose to light. Requires scarification. Nick or rub between sheets of sandpaper. Requires soaking. Place in warm water until seeds swell, usually 24-48 hours. Discard water and any seeds that remain floating. * immerse in boiling water for 20 seconds