Western Juniper Juniperus scopulorum
Other Common Name(s):
Previously known as:
- Juniperus scopulorum var. columnaris
- Juniperus virginiana ssp. scopulorum
- Juniperus virginiana var. montana
- Juniperus virginiana var. scopulorum
- Sabina scopulorum
- Phonetic Spelling
- ju-NIP-er-us skop-u-LO-rum
- Description
-
Rocky Mountain Juniper is a native slow-growing, conifer, evergreen needled tree in the Cupressaceae or cypress family. It is narrow, pyramidal to rounded in form and grows 30-40 feet tall. It has shedding reddish-brown bark and has bluish-silvery to dark green scale-like foliage that lies flat against the branches. The seed cones are waxy blue, and berry-like which are a source of food for birds and small mammals.
Rocky Mountain juniper is one of thirteen junipers that are native to North America. It is found in the western United States and Canada. The tree can be found in drier mountains and foothills of British Columbia and Alberta, the Rocky Mountains to Arizona, New Mexico, and western Texas. It is also found in mixed or pure stands of open woodland areas in Wyoming and Colorado at elevations of up to 7500 feet, often on dry and rocky ridges.
The genus name, Juniperus, is derived from the Latin word for juniper. The epithet, scopulorum, is from the Latin word that translates "of the cliffs or rock' and refers to the species mountainous habitat.
The Rocky Mountain Juniper prefers full sun, moist, well-drained soils and especially does well in dry, sandy soil. It is drought, salt spray, erosion, dry soil, and air pollution tolerant. The tree will adapt to various soil types that may be on the dry side.
It cannot tolerate wet soils, high humidity, nor high night temperatures. They are also intolerant to ice. The Rocky Mountain Juniper is very susceptible to injury or death from fires due to it thin, stringy bark and the volatile oils contained in the branches.
It is possible the Rocky Mountain Juniper could be attempted in the mountains of North Carolina. It may be best to consider the closely related to the Eastern Red Cedar for use in the landscape, which is better able to handle the hot, humid weather of North Carolina.
Quick ID Hints:
- bark is reddish-brown or gray, exfoliates in thin strips.
- small branchlets are smooth, but larger branchlets exfoliate in plates.
- adult foliage is opposite, simple scale-like and varies in color from bluish-silvery or light to dark green
- juvenile foliage is more needle-like
- male and female flowers on separate plants, female flowers are greenish-yellow and have two ovules, male flowers are yellow with six stamens and appear on short branchlets.
- the fruit is a round, immature berry is green and glaucous, ripens to a bluish-purple with a white, waxy bloom.
Insects, Diseases, and Other Plant Problems: Rocky Mountain Juniper has no serious diseases or insect pests. In rainy or wet springs, they may be susceptible to blights which causes the dieback of the stem tips. Phomopsis twig blight may occur as well as Cedar-apple rust and other rust diseases. In poorly drained soils, root rot can occur. Aphids, bagworms, twig borers, webworms, scale, and spider mites are potential insect pests. In the wild, animals just the tree as a rubbing post and causes damage to the stems and roots.
The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common juniper diseases and insect pests.
VIDEO created by Ryan Contreras for “Landscape Plant Materials I: Deciduous Hardwoods and Conifers or Landscape Plant Materials II: Spring Flowering Trees and Shrubs” a plant identification course offered by the Department of Horticulture at Oregon State University
- Profile Video:
- See this plant in the following landscape:
- Cultivars / Varieties:
-
- 'Blue Arrow'
narrow, upright, blue green foliage - 'Blue Creeper'
low growing, mounding, blue foliage
'Blue Heaven"
- 'Cologreen'
upright, narrow, green foliage - 'Gray Gleam'
slow-growing, dense, columnar, silver-gray foliage
'Pathfinder'
- 'Snow Flurries'
narrow shrub, columnar to fastigiate, blue foliage with creamy white spots
'Table Top'
- 'Wichita Blue'
compact, conical, blue to blue gray foliage, male
Light blue conical bush
broad, pyramidal, bluish-green foliage in flat sprays
low growing, flat-topped, silvery-blue foliage, female - 'Blue Arrow'
- 'Blue Arrow', 'Blue Creeper', 'Blue Heaven", 'Cologreen', 'Gray Gleam', 'Pathfinder', 'Snow Flurries', 'Table Top', 'Wichita Blue'
- Tags:
- Cultivars / Varieties:
-
- 'Blue Arrow'
narrow, upright, blue green foliage - 'Blue Creeper'
low growing, mounding, blue foliage
'Blue Heaven"
- 'Cologreen'
upright, narrow, green foliage - 'Gray Gleam'
slow-growing, dense, columnar, silver-gray foliage
'Pathfinder'
- 'Snow Flurries'
narrow shrub, columnar to fastigiate, blue foliage with creamy white spots
'Table Top'
- 'Wichita Blue'
compact, conical, blue to blue gray foliage, male
Light blue conical bush
broad, pyramidal, bluish-green foliage in flat sprays
low growing, flat-topped, silvery-blue foliage, female - 'Blue Arrow'
- 'Blue Arrow', 'Blue Creeper', 'Blue Heaven", 'Cologreen', 'Gray Gleam', 'Pathfinder', 'Snow Flurries', 'Table Top', 'Wichita Blue'
- Tags:
-
-
Attributes:
- Genus:
- Juniperus
- Species:
- scopulorum
- Family:
- Cupressaceae
- Uses (Ethnobotany):
- The aromatic wood is used for cedar chests and for lumber, fence posts, and fuel. Native Americans used the juniper berries for food and decorations. The bark was woven to make cradles. It was also used for firewood for heating and cooking. When the wood is cured, it is resistant to decay.
- Life Cycle:
- Woody
- Recommended Propagation Strategy:
- Seed
- Stem Cutting
- Country Or Region Of Origin:
- Western Canada, western USA to Northern Mexico
- Distribution:
- Native: Canada--British Columbia and Alberta, Mexico Northeast, Mexico Northwest, and the United States--CO, ID, MT, NE, NV, NM, ND, OR, SD, UT, WA, and WY.
- Fire Risk Rating:
- high flammability
- Wildlife Value:
- Birds eat the cones. It provides nesting sites and cover. Host plant to the olive butterfly. Deer resistant.
- Play Value:
- Wildlife Cover/Habitat
- Wildlife Food Source
- Dimensions:
- Height: 30 ft. 0 in. - 40 ft. 0 in.
- Width: 3 ft. 0 in. - 15 ft. 0 in.
-
-
Whole Plant Traits:
- Plant Type:
- Tree
- Woody Plant Leaf Characteristics:
- Needled Evergreen
- Habit/Form:
- Columnar
- Erect
- Pyramidal
- Rounded
- Growth Rate:
- Slow
- Maintenance:
- Low
- Texture:
- Medium
-
-
Cultural Conditions:
- Light:
- Full sun (6 or more hours of direct sunlight a day)
- Partial Shade (Direct sunlight only part of the day, 2-6 hours)
- Soil Texture:
- Clay
- Loam (Silt)
- Sand
- Shallow Rocky
- Soil Drainage:
- Good Drainage
- Moist
- Occasionally Dry
- Available Space To Plant:
- 12-24 feet
- NC Region:
- Mountains
- USDA Plant Hardiness Zone:
- 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b
-
-
Fruit:
- Fruit Color:
- Blue
- Display/Harvest Time:
- Fall
- Winter
- Fruit Type:
- Berry
- Fruit Length:
- < 1 inch
- Fruit Width:
- < 1 inch
- Fruit Description:
- The fruit is a round, two-lobed, 0.2 to 0.3 inches in diameter, dark blue, heavily glaucous, and a berry-like cone. The immature berry is green and glaucous. It ripens to a bluish-purple with a white, waxy bloom. The seed cone is resinous to fibrous and contains 1 to 3 brownish seeds that are 4-5 mm in diameter. They ripen the second year from mid-September to mid-December. They remain on the tree until the following spring. The seeds are dispersed mainly by birds.
-
-
Flowers:
- Flower Color:
- Gold/Yellow
- Green
- Flower Inflorescence:
- Insignificant
- Flower Bloom Time:
- Spring
- Flower Description:
- The tree is dioecious or produces male and female flowers on separate plants. Both male and female flowers are present from mid-April to mid-June. The female flowers are greenish-yellow and have two ovules. They open in the following spring before pollination. The male flowers are yellow with six stamens and appear on short branchlets. The pollen is dispersed by the wind. The female flowers have 3 to 8 pointed scales that become fleshy and fuse to form a small strobili or berry.
-
-
Leaves:
- Woody Plant Leaf Characteristics:
- Needled Evergreen
- Leaf Color:
- Blue
- Gray/Silver
- Green
- Leaf Value To Gardener:
- Fragrant
- Deciduous Leaf Fall Color:
- Insignificant
- Leaf Type:
- Simple
- Leaf Arrangement:
- Opposite
- Leaf Margin:
- Entire
- Hairs Present:
- No
- Leaf Length:
- < 1 inch
- Leaf Width:
- < 1 inch
- Leaf Description:
- Adult foliage is opposite, scale-like and varies in color from bluish-silvery or light to dark green. They usually have an inconspicuous gland on the surface of the leaf. The leaves are appressed or spreading and measure 1 to 3 mm long. The juvenile foliage is more needle-like, measures 5 to 7 mm long, and pointed with white coated needles. The foliage has a musty scent.
-
-
Bark:
- Bark Color:
- Light Brown
- Light Gray
- Red/Burgundy
- Surface/Attachment:
- Exfoliating
- Bark Description:
- The bark is reddish-brown or gray and sheds or exfoliates in thin strips.
-
-
Stem:
- Stem Is Aromatic:
- No
- Stem Description:
- The small branchlets are smooth, but larger branchlets exfoliate in plates.
-
-
Landscape:
- Landscape Location:
- Lawn
- Design Feature:
- Screen/Privacy
- Small Tree
- Attracts:
- Butterflies
- Songbirds
- Resistance To Challenges:
- Deer
- Drought
- Dry Soil
- Pollution
- Salt
