Native to the cool, temperature climates of the northern hemisphere, common junipers (Juniperus communis) have a nearly complete circumpolar distribution - occurring naturally throughout parts of North America, Europe, and Asia. This makes the common juniper one of the most widely distributed shrubs in the world.
Common junipers are evergreen coniferous trees/shrubs in the family Cupressaceae. These hardy conifers are variable in form, typically depending on where they are located. They range from a tall, tree-like form that can reach up to 50 feet tall, to a short shrub with a spreading growth habit that rarely grows more than 5 feet in height. They are characterized by needle-like, aromatic leaves and berry-like green cones that turn a deep purple/blue as they ripen.
Common junipers have many different practical uses. In their native regions, the berries are enjoyed by many different species of birds and wildlife and are utilized by humans too. The flavorful berries are a prominent ingredient in gin, and can also be used to make tea and flavor cooked meats and vegetables.
|Botanical Name||Juniperus communis|
|Common Name||Common juniper|
|Plant Type||Evergreen conifer|
|Mature Size||2-50' tall|
|Sun Exposure||Full sun|
|Soil pH||Not particular|
|Flower Color||Not ornamentally significant|
|Native Area||North America, Europe, Asia|
How to Grow Common Juniper
For the most part, common junipers are fairly self-sustaining and do not require much attention. They are extremely hardy shrubs that can adapt to a wide range of growing conditions including poor soils, dry locations, and even inner-city environments as common junipers are highly tolerant of urban pollution. Common junipers are slow-growing shrubs that are great for mass plantings, groundcover, rock gardens, and general garden use. They do not require heavy pruning but can be lightly pruned to shape in the late winter once the worst of the cold has passed.
Common juniper is a sun-loving evergreen that should receive full sun for the majority of the day. If a common juniper does not receive enough light you may notice stalled or stunted growth. Common junipers cannot survive in full shade conditions.
When it comes to soil, common junipers are not picky as long as the medium provides good drainage. They are highly adaptable to a wide range of soil conditions and they are not particular about soil pH - growing well in soils that are highly alkaline to highly acidic. Common junipers are also known to grow easily on a wide range of different sites including exposed slopes and plateaus; wooded hillsides; sand terraces and dunes; maritime escarpments; and dry, open, and rocky environments.
Common junipers are considered to be drought-tolerant shrubs but are adaptable to both dry and wet conditions. However, they cannot withstand being waterlogged or sitting in standing water, so appropriate drainage is imperative for the common juniper. When grown in their native range, common junipers do not require any supplemental watering.
Temperature and Humidity
Common junipers are native to the cool temperate climates of the Northern Hemisphere, and as such are tolerant of a wide range of temperatures. At their maximum, common junipers can withstand winter temperatures as low as -45 degrees Celsius (or -49 degrees Fahrenheit), and may frequently experience summer temperatures as high as 30 degrees Celsius (or 80 degrees Fahrenheit). Common junipers grow well in USDA zones 2 through 7.
These hardy shrubs are considered ‘light feeders’ and do not require regular fertilization. If desired, established common junipers can benefit from a yearly feeding in the late winter to early spring with a slow-release shrub and tree fertilizer, but this is not necessary.
How to Grow Common Juniper From Seed
When it comes to propagation, common junipers are most readily grown from seeds. Common junipers are dioecious, meaning that individual trees are either male or female, and must be planted nearby the opposite sex in order to cross-pollinate and produce fruit. Once the fruit of the common juniper has ripened (turned from green to purple-black), the seeds can be harvested and either sowed directly into the garden or stored over the winter to be sowed in the spring.
If you are not sowing the seeds immediately, they should be cleaned and air-dried to prevent the formation of mold. Common juniper seeds require cold-stratification in order to germinate and must be kept in an airtight container at 20-40 degrees Fahrenheit for up to 120 days prior to planting. Because common juniper germination rates are notoriously poor, it's a good idea to sow several seeds at once for the best chances of success.
Common junipers are susceptible to a number of common pests and diseases. Watch out for diseases such as juniper blight, twig blight, and cedar apple rust - all of which can be handled with prompt and aggressive pruning. Common pests of the common juniper include bagworms, juniper scale, aphids, and more. Checking the shrub over semi-annually for signs of pests and using an insecticide when needed should keep any major infestations under control.