Whitethorn Ceanothus

Scientific Name: Ceanothus cordulatus Kellogg

Classification: Plantae/ Tracheobionta / Spermatophyta / Magnoliophyta / Magnoliopsida / Rosidae / Rhamnales / Rhamnaceae / Ceanothus L./ Ceanothus cordulatus Kellogg

Whitethorn Ceanothus
General Information
Usda SymbolCECO
GroupDicot
Life CyclePerennial
Growth HabitsShrub
Native LocationsCECO

Plant Guide

Alternative Names

Snowbush

Uses

Mountain whitethorn can be used for ground cover on slopes, terraces or steep banks and as a barrier plant. Mountain whitethorn may be allowed to assume natural forms or may be shaped through pruning and pinching off the growing tips.

Status

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).

Description

Buckthorn Family (Rhamnaceae). Mountain whitethorn is a densely branched, spiny, evergreen, flat-topped native shrub, which reaches heights of 2 to 5 feet. However, at elevations, such as the Lake Tahoe Basin, it assumes a low spreading growth form. Individual plants may spread to form continuous ground cover over areas with a diameter up to 12 feet. The numerous stems terminate in a hard sharp point thus, the name whitethorn. Whitethorn flowers form in a small, dense cluster 1 to 2 inches long. The flowers, which bloom from late spring to mid summer, have a heavy penetrating fragrance. During the flowering season, the abundant white flowers may cause areas to appear covered with snow.

Distribution

California, Nevada, and Southwest Oregon. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site. © Gary A. Monroe @ plants.usda.gov

Adaptation

Mountain whitethorn is well suited to dry open flats and rocky slopes with well-drained soils. Seed Establishment, Production and

Management

Mountain whitethorn seeds mature in late August and September. The seeds are contained within a triangular capsule. Collected capsules should be stored in paper bags and allowed to dry until they open and reveal the seeds. The seed has a hard exterior coat and therefore a combination of soaking in hot water and cold storage pretreatments are necessary. Seeds should be placed in hot water, preheated to 180 degrees F., and then allowed to cool and soak for 24 hours. Following this hot water treatment, mix the seed with moist sand, place the mixture in plastic bags and store in the refrigerator. Periodically check the bags for moisture and for swelling of the seed which indicates that they are close to germinating. Once the seeds have swollen, plant them in containers of potting soil and cover them with approximately ½ inch of soil. After the plants have formed a third pair of leaves they can be transplanted individually to larger ½ to 1 gallon containers. The young plants will be ready for their permanent location in 1 ½ to 2 years. New plants should be watered occasionally until they are well established. Afterward, deep watering every 1 to 1 ½ months will be adequate to maintain uniform growth. Container grown plants may be available from local nurseries. Dig a hole two to three times the diameter of the root ball and at least six inches deeper. Backfill the hole with six inches of native soil. Make a few, 1/8 inch deep vertical cuts in the root ball, or carefully “tease” roots away from the root ball with your hands to encourage roots to grow into the new soil. Set the plant into the hole and fill in around the roots, firming the soil with your hands as you fill, until the hole is half full. Fill the hole with water and allow it to settle. This will settle the silt and eliminate air pockets around the roots. Backfill with enough planting mix so the plant will set at the same level it was growing at in the container. Water to allow soil to settle, then add more soil if necessary. Build a berm of soil to form a watering basin around the outer edge of the hole. Break the basin down after two or three years.

Pests and Potential Problems

Fairly free from diseases, but is susceptible to crown and root problems related to agricultural soils and wet and poorly drained soils, Cultivars, Improved, and Selected Materials (and area of origin) ‘Maleza’ Cultivar: This was released by the Lockeford,Plant Materials Center, Lockeford, California in 1989, Maleza mountain whitethorn is well suited for medium to coarse textured, well-drained soils, Use soil moisture sensors to measure the soil moisture of Whitethorn Ceanothus., It is adapted to the Tahoe Basin, but grows well at elevations down to 3500 feet where precipitation is adequate, Contact your local Natural Resources

Conservation

Service (formerly Soil Conservation Service) office for more information. Look in the phone book under ”United States Government.” The Natural Resources Conservation Service will be listed under the subheading “Department of Agriculture.”

Plant Traits

Growth Requirements

Cold Stratification RequiredNo
Hedge ToleranceLow
Hedge ToleranceHigh
Frost Free Days, Minimum90
Frost Free Days, Minimum135
Fire ToleranceHigh
Fire ToleranceHigh
Fertility RequirementMedium
Fertility RequirementLow
Drought ToleranceLow
Drought ToleranceHigh
Cold Stratification RequiredNo
Temperature, Minimum (°F)-23
CaCO3 ToleranceHigh
CaCO3 ToleranceHigh
Anaerobic ToleranceNone
Anaerobic ToleranceNone
Adapted to Medium Textured SoilsYes
Adapted to Medium Textured SoilsYes
Adapted to Fine Textured SoilsNo
Adapted to Fine Textured SoilsNo
Adapted to Coarse Textured SoilsYes
Adapted to Coarse Textured SoilsYes
Moisture UseLow
Temperature, Minimum (°F)-23
Shade ToleranceIntolerant
Shade ToleranceIntermediate
Salinity ToleranceNone
Salinity ToleranceLow
Root Depth, Minimum (inches)20
Root Depth, Minimum (inches)20
Precipitation, Minimum16
Precipitation, Minimum16
Precipitation, Maximum60
Precipitation, Maximum46
Planting Density per Acre, Minim700
Planting Density per Acre, Minim682
Planting Density per Acre, Maxim4800
Planting Density per Acre, Maxim2728
pH, Minimum7.0
pH, Minimum6.3
pH, Maximum8.5
pH, Maximum8.3
Moisture UseLow


Morphology/Physiology

Active Growth PeriodSpring and Summer
ToxicityNone
ToxicityNone
Shape and OrientationSemi-Erect
Fire ResistantNo
Foliage TextureMedium
Foliage TextureFine
Foliage Porosity WinterModerate
Foliage Porosity WinterModerate
Foliage Porosity SummerDense
Foliage Porosity SummerDense
Foliage ColorGreen
Foliage ColorGreen
Flower ConspicuousYes
Flower ConspicuousYes
Flower ColorWhite
Flower ColorWhite
Resprout AbilityYes
Fire ResistantNo
Fall ConspicuousNo
Fall ConspicuousNo
Coppice PotentialNo
Coppice PotentialNo
C:N RatioLow
C:N RatioLow
BloatNone
BloatNone
Active Growth PeriodSpring and Summer
Shape and OrientationSemi-Erect
Fruit/Seed ColorBrown
Resprout AbilityYes
Nitrogen FixationMedium
Nitrogen FixationLow
Low Growing GrassNo
Low Growing GrassNo
LifespanLong
LifespanLong
Leaf RetentionNo
Leaf RetentionNo
Known AllelopathNo
Known AllelopathNo
Height, Mature (feet)5.0
Height, Mature (feet)8.0
Fruit/Seed ColorBrown
Fruit/Seed ConspicuousNo
Fruit/Seed ConspicuousNo
Growth FormMultiple Stem
Growth FormThicket Forming
Growth RateSlow
Growth RateSlow
Height at 20 Years, Maximum (fee4
Height at 20 Years, Maximum (fee5


Reproduction

Propagated by CuttingsNo
Propagated by SeedYes
Propagated by SeedYes
Propagated by SodNo
Propagated by SodNo
Propagated by SprigsNo
Propagated by SprigsNo
Propagated by TubersNo
Propagated by TubersNo
Seed per Pound166000
Fruit/Seed Period EndFall
Seed per Pound166000
Seed Spread RateModerate
Seed Spread RateSlow
Seedling VigorLow
Seedling VigorMedium
Small GrainNo
Small GrainNo
Vegetative Spread RateNone
Vegetative Spread RateSlow
Propagated by CormNo
Propagated by CuttingsNo
Bloom PeriodEarly Summer
Bloom PeriodEarly Summer
Commercial AvailabilityField Collections Only
Commercial AvailabilityRoutinely Available
Fruit/Seed AbundanceHigh
Fruit/Seed AbundanceHigh
Fruit/Seed Period BeginSummer
Fruit/Seed Period BeginSummer
Fruit/Seed Period EndFall
Fruit/Seed PersistenceNo
Propagated by Bare RootYes
Propagated by Bare RootYes
Propagated by BulbNo
Propagated by BulbNo
Propagated by ContainerYes
Propagated by ContainerYes
Propagated by CormNo
Fruit/Seed PersistenceNo


Suitability/Use

Palatable Browse AnimalHigh
Palatable Graze AnimalLow
Palatable Graze AnimalMedium
Palatable HumanNo
Palatable HumanNo
Post ProductNo
Post ProductNo
Protein PotentialLow
Protein PotentialLow
Pulpwood ProductNo
Pulpwood ProductNo
Veneer ProductNo
Veneer ProductNo
Palatable Browse AnimalHigh
Nursery Stock ProductYes
Nursery Stock ProductNo
Naval Store ProductNo
Naval Store ProductNo
Lumber ProductNo
Lumber ProductNo
Fodder ProductNo
Fodder ProductNo
Christmas Tree ProductNo
Christmas Tree ProductNo
Berry/Nut/Seed ProductNo
Berry/Nut/Seed ProductNo

Whitethorn Ceanothus

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