Common juniper (Juniperus communis) has the largest geographical range of any conifer in the world. It grows from the North Polar region to as far south as roughly 30 degrees latitude. It is most often seen as a sprawling groundcover plant with soft-looking blue-green needles.
Here is a map showing its native range. In its southernmost areas, it tends to grow at high altitudes.
Some people know of juniper from its berries, which can be used to flavour gin, or to garnish a gin and tonic. It therefore is important in the History of Gin and Tonic. Juniper berries are actually the cones of the female juniper plant. They are green for the first year, and then become bluish-black in their second year. In addition to their use in drinks and baking, they also may help to treat diabetes, cystitis or kidney problems.
You may find you already have a juniper plant growing in your garden, in a protected niche behind your house, where birds dropped the seeds. Birds feast on juniper berries in the winter. 'They’re one of the top 10 plants for wildlife,' says one observer. If you don't have a cadre of helpful birds to plant your juniper for you, you may buy it from a garden centre. Here are some guidelines:
Look for needles that are a rich green. Too many brown needles is a sign of ill health
Choose a sunny spot. Junipers often grow in the mountains, and enjoy unobstructed sun.
Plant in well-drained soil. Sandy mountain soil is a given in their original habitat.
Plant after the ground thaws in the spring. Mid-autumn is another option.
Water once or twice a week for the first two months, to get the plant established. Once established, it should be drought-resistant, within reason. In a severe drought, you may want to water.
You may use a small amount of fertiliser once a year in early spring. Some fertilisers are specifically designed for junipers.
You don't need to cover your junipers for the winter as established plants are hardy to -40 degrees.
Common Juniper may come in different forms, among them a low-growing plant that sprawls, or a tall, thin one. The most common use of the plant is as groundcover, especially in rock gardens. If you wish to avail yourself of the berries, be sure to plant multiple junipers. The berries only appear on the female plants, but both males and females are needed in reasonable proximity to make the berries possible, so plant accordingly.