Creeping Juniper

Creeping juniper is a species of graceful, aromatic, low-growing, evergreen shrubby conifers native to the boreal and subarctic regions in North America, though some populations are also scattered further south in America. Featuring plume-like horizontal branches, the creeping junipers have blue-green foliage in both spring and summer, turning into dark purple in winter.

Scientific Classification

Kingdom	Plantae
Division	Pinophyta
Class	Pinopsida
Order	Pinales
Family	Cupressaceae
Genus	Juniperus
Scientific Name	Juniperus horizontalis

Quick Information

Other Names	Trailing juniper, creeping cedar, creeping savin juniper
Other Related Species	Juniperus virginiana, Juniperus scopulorum
Size	10-30 cm tall, spread 1.8-3.1 m (6-10 ft) wide
Leaves	Occur in opposite crossed pairs, sometimes forming whorls of three; scale-like adult leaves (1-2 mm long, 1-1.5 mm broad) and needle-like juvenile leaves (5-10 mm long)
Cones	Berry-like, globular to bilobate, diameter of 5-7 mm, dark blue with bluish-white flowers having a waxy texture, usually contain 2 seeds, male cones have a length of 2-4 mm, pollens  are shed in spring
Bark	Reddish brown, peeled, difficult to spot due to overlapping branches
Distribution/Range	Alberta, Labrador, British Columbia, Newfoundland I, Manitoba, Nova Scotia, Yukon, Quebec, Ontario, Saskatchewan, Northern Territories (in Canada); Iowa, Illinois, Michigan, Massachusetts, Montana, Minnesota, Colorado, New York, Vermont, Wyoming, Wisconsin, North and South Dakota (in the US)
Hardiness Zones	3-10
Growth Rate	Medium with an annual increase of about 4.6 cm
Lifespan	Moderate
Growing Conditions	Winter Conditions: Arid, cold climate with average January temperature of -14.5 °C to -10 °C Summer Conditions: Typically dry with great variations in diurnal and annual temperatures; average July temperature is 18.8 °C, tolerates summer drought conditions Rain: Needs low/moderate amount of rainfall, grows in areas with average yearly precipitation of 12.9-18 inches Sunlight: Grows well under full sun; tolerant to partial sunlight but may have thin foliage Soil Requirements: Medium moist, well-drained, dry, sandy, loamy, acidic or slightly alkaline
Diseases and Pests	Affected by root rots, phomopsis dieback, foliage blight, cedar apple rust; serious pests including juniper scale, juniper webworm, twig borers, bagworms
Pollination	Through wind
Breeding System	Dioecious
Seed Production	Poor seed producer; seeds are dispersed by wind and wildlife
Development	Staminate/pistillate cones are produced in the spring; they mature in summer/early fall
Wildlife Value	Mule deer, white-tailed deer, pronghorn, and other small mammals feed on this plant; birds such as rose-breasted grosbeaks, yellow warblers, clay-colored sparrows, catbirds, blue jays, black-billed cuckoos, chipping sparrows, and brown thrashers use creeping juniper habitats
Uses	Cultivars are used in horticulture and landscaping, makes a great ground cover in rockeries and on sandy soils; also used for erosion control
IUCN Conservation Status	Least Concern

Cultivars/Varieties

• ‘Wiltonii’: Also called the ‘Blue Rug,’ the prostrate juniper has bluish foliage with a diameter of 5 ft and height of 4-6 inches.
• ‘Plumosa’ or ‘Andorra Juniper’: This variety of junipers is widely used in landscaping despite being highly susceptible to blight. It has a spread of 10 ft and grows up to 2 ft tall.
• ‘Bar Harbor’: Originating from Mount Desert Island, this juniper plant is an excellent prostate groundcover. It grows 1 ft high and spreads to about 6 ft.
• ‘Blue Prince’: This flat-growing variety with fine blue needles grows 6 inches high and spreads up to 5 ft.

There are other cultivars including ‘Blue Chip’, ’Mother Lode’, ’Hughes’, ’Monber’, and ‘Prince of Wales’.

Interesting Facts

• The berry-like seed cones of creeping juniper plants were used by the Native Americans for making an infusion to treat colds, sore throats, and kidney diseases.

References

1. https://en.wikipedia.org/wiki/Juniperus_horizontalis
2. http://www.gardeningknowhow.com/ornamental/shrubs/juniper/growing-creeping-junipers.htm
3. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233500732
4. http://www.iucnredlist.org/details/42237/0
5. http://www.hort.uconn.edu/plants/detail.php?pid=229