Culture
Winter hardy to USDA Zones 2-6 where it is best grown in medium moisture, well-drained soils in full sun. Tolerates a wide range of soils, including very poor often rocky soils. Established plants have good drought tolerance. Species plants are particularly noted for their superior tolerance for cold temperatures and superior intolerance for heat and humidity. Plants will survive in the wild within the Arctic Circle, but are not recommended for planting in locations south of USDA Zone 6.
Noteworthy Characteristics
Juniperus communis, commonly called common juniper, is a dioecious, needled, evergreen conifer that grows in a variety of different shapes and forms in cool to cold areas of the Northern Hemisphere plus in one isolated population growing in the Atlas Mountains of Africa. It is the most widespread conifer growing in the world today. It is primarily native to coniferous forests, alpine open areas and plains in a circumpolar distribution which includes sites in Europe, Asia and North America, extending in some cases to within the Arctic Circle. In North America, it is widespread from Alaska east to Labrador and Greenland south to Minnesota and New York, extending further south in the Rocky Mountains to Arizona and in the Appalachians to North Carolina.
Growth habit and form in part depend upon such factors as geographic location, temperature and the amount of exposure to the elements. However, it is not unusual for a variety of different forms to be found growing together in the same location. In the U.S., common juniper is most frequently seen as a multi-stemmed shrub (to 5-15’ tall), but is also sometimes seen, particularly in harsh growing conditions, as a prostrate, low-growing, spreading shrubby plant (to 9-12” tall). Infrequently it appears as a medium-sized tree rising to as much as 45’ tall. Prickly, green, needle-like juvenile leaves grow in whorls of three. A glaucous stomatal band appears on each adaxial leaf surface. Adult foliage never appears. Exfoliating bark is often an attractive reddish-brown. Small yellow spring flowers (April-June) are not ornamentally attractive, but give way on female plants to slightly glaucous, spherical, 1/2” diameter seed cones (fruits) which are commonly referred to as juniper berries. Berries emerge green but gradually ripen by fall to a waxy dark blue to black. Each berry usually contains two or three seeds and ripens in the 2nd or 3rd year. Berries are used for a number of purposes including, perhaps most notably, as the dominant flavoring of gin (the alcoholic beverage).
Var. depressa occurs naturally in eastern North America and is vigorous and cold hardy. It is a prostate plant that rarely exceeds 4' in height and tolerates dry, sandy, stony and gravelly soil. Foliage turn bronze in winter.
Genus name comes from the Latin name for the juniper.
Specific epithet means common.
‘Amidak’ originated from a variety growing in the Badlands of western North Dakota and is sold under the registered trade name of BLUEBERRY DELIGHT®. It is a low growing, densely spreading evergreen that is effective as a foundation planting. The foliage is a rich, dark green with contrasting silvery-blue hues on the upper leaf surface. The summer color is retained well into winter. If a male plant is nearby, heavy crops of showy blueberry-like cones are produced annually.
Problems
No serious insect or disease problems. Juniper blight can be a serious problem on many of the different species of juniper, but is less frequently a problem on J. communis. Lesser problems include cedar apple rust and wilt. Insect problems include mites, borers, scale, midges and bagworms.
Uses
Evergreen ornamental ground cover, shrub or small tree. Use depends in large part upon form and size. Species plants are rarely sold in commerce, but a large number of varieties and cultivars are available.