Gerald L. Klingaman
Plant Common Name
There are around 60 species in the genus Juniperus which are primarily distributed in temperate, often semi-arid regions across the Northern Hemisphere, from Arctic regions to tropical Africa and the mountains of Central America. These tough, adaptable evergreens make valuable landscape specimens, but some also have medicinal qualities and their berries can be used to flavor meats and stews. Some species are known for their hard, fragrant, insect-repellent wood.
Junipers are variable in size and shape. They may be tall trees or low, spreading shrubs. The trunks and stems are covered with thin bark which tends to exfoliate with age, peeling in long, thin, papery strips. Their branches may be cylindrical or angled. Junipers have two foliage forms, both of which may appear on the plant at the same time. The juvenile leaves are prickly, needle-like, and arranged in opposite, alternating pairs or in whorls of three. The scale-like mature foliage is usually overlapping and held close to the stem.
Junipers reproduce through separate male and female cones which are typically borne on separate plants, although some species bear both sexes on the same plant. The male cones are oval or oblong, scaly, and covered with yellow, pollen-producing structures. Wind carries pollen to the rounded, berry-like female structures, which may be blue or sometimes red-brown, and either fleshy or woody, and smooth or scaly. These contain small, wingless seeds that may take from six months to three years to mature, at which point the cones drop from the plant. The seeds are often dispersed by birds, who relish the female cones as a food source.
Among this group of versatile, utilitarian evergreens, one of the most widely-grown species is Chinese juniper (). Native to China and Japan, it varies widely in habit and has numerous cultivated forms. Creeping juniper (Juniperus horizontalis) is a low-growing species native to North America, which is a highly useful groundcover. Eastern red cedar (Juniperus virginiana) is a large tree native to the eastern United States prized for its colorful, aromatic wood. The female cones of some species, notably the broadly-distributed common juniper (Juniperus communis), have long been used in Europe as a culinary seasoning and flavoring for gin.
From tiny rock garden types to spreading groundcovers, large hedge forms and tall trees, there is a juniper for almost every landscape. Growth requirements are species dependent but generally, most prefer full sun and soils with good drainage. They are often drought tolerant once established, making them very useful for hot, dry, sunny locations.