Whitethorn Ceanothus

Ceanothus cordulatus

Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Rhamnaceae
Genus:
Ceanothus
Species:
Ceanothus cordulatus

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Shrub
Height:
6-8 ft
Light Requirements:
Full Sun
Drought Tolerance:
High
Bloom Months:
may, jun, jul
Bloom Colors:
White
Evergreen Shrub:
Yes
Landscaping Shrub:
Yes

Native Range

United States: California, Nevada, Oregon

Keystone Species Ranking

Caterpillar Keystone:
★★☆☆☆ Based on number of butterfly and moth species using this genus as host plant (Source: National Wildlife Federation)

Host Plant for Caterpillars

Ceanothus Silkmoth (Hyalophora euryalus), Columbia silk moth (Hyalophora columbia), Drepanulatrix carnearia, Drepanulatrix nevadaria, Drepanulatrix quadraria, Kaslo silkmoth (Hyalophora "kasloensis"), Saturnia albofasciata, Western tent caterpillar (Malacosoma californica), California tortoiseshell (Nymphalis californica), Pacuvius Duskywing (Erynnis pacuvius), Pale Swallowtail (Papilio eurymedon)

Reported Fauna Sightings

Bees: Black-tailed bumble bee (Bombus melanopygus), Black-tailed bumble bee (Bombus melanopygus), Fuzzy-horned bumble bee (Bombus mixtus), Fuzzy-horned bumble bee (Bombus mixtus), Two-form bumble bee (Bombus bifarius), Two-form bumble bee (Bombus bifarius), van Dyke bumble bee (Bombus vandykei), van Dyke bumble bee (Bombus vandykei), Yellow-faced bumble bee (Bombus vosnesenskii), Yellow-faced bumble bee (Bombus vosnesenskii)

Soil Requirements

Soil Type:
rocky, well-drained, nutrient-poor soil
pH:
5.5 - 7.5 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
prefers open, sunny locations in native range

Germination Information

Pre-treatment: Seeds are placed in fine mesh bags, soaked for 10 seconds in boiling water and then immediately transferred in cold water. Seeds are then placed into a 1% hydrogen peroxide (3:1 water/3% hydrogen peroxide) soak for 24 hours, rinsed, and placed in water for an additional 4 hours. Seeds are sown into trays filled with stabilized medium plugs (Q-plugs). Trays are sealed inside plastic bags and placed into refrigeration at 1 to 3 °C for 90 days. Trays are checked weekly and kept moist throughout the stratification period. If mold is evident, trays should be treated with 1% hydrogen peroxide.

Establishment: Ceanothus cordulatus, also known as whitethorn ceanothus or white ceanothus, is generally found in Oregon, California, Nevada and within mattoral vegetation association of California. There is a variation in the pre-planting propagule treatments across the protocols, with one suggesting that seeds germinate at greenhouse temperatures without any specific treatment.

Source: npn.rngr.net