Juniperus

Blue star juniper is native to the Himalayas and north-west China’s mountains at elevations between 1600-4800m. Its habit is variable, like most other junipers: it can grow as a small tree or as a prostrate creeper, but most commonly is an erect shrub.

The blue star’s branch tips droop attractively. The bluish needle leaves – varying in shade from blue-green to strongly bluish - are in groups of three, broad and curved, with sharp tips. In colder months they take on shades of brown and bronze.

Creeping juniper grows naturally over a large area of northern North America, from Newfoundland to near the Arctic Ocean, on rocky shores, in the mountains, in nutrient-poor forests and on bogs. It is hardy to heat and cold, enjoys full sun but also tolerates a degree of shade.

Rocky Mountain juniper grows throughout the mountainous areas of western North America, mainly above 1500 metres elevation. In places it forms large thickets giving a characteristic appearance to the landscape. It can grow into an erect, pillar-shaped or conical tree to 10 metres, or an irregular round shrub with strong branching from the base.

Savin grows naturally in south-east Europe, the Alps and Carpathians, eastern Siberia and central Asia at elevations 1000-3300m. It is found at the forest limit in mountain areas and also in the under-storey of mountain forests. There is a form of savin, J. sabina var. davurica which grows in eastern Asia and has both scale-like and needle-like leaves in mature plants. The European savin has only scale-like leaves.

Juniper has the greatest range of any conifer. It grows on all the continents of the Northern Hemisphere from the Arctic tundra to the semi-tropics. This demands great adaptability to varying conditions, and juniper is indeed undemanding as to where it grows: from almost bare rock to nutrient-rich groves.

Juniper’s habit varies: creeper, shrubby or erect, sometimes even tree-like, with other intermediate forms. Particular forms are also selected for production and sale as “varieties”.

Sargent juniper is from the extreme east of Asia; it was received at Boston’s Arnold Arboretum from Japan’s Hokkaido Island in 1892 and named after the arboretum’s first director C. S. Sargent (1841-1927). The species also grows on all the other Japanese islands, the Korean peninsula, the Kuriles, and in the south of Sakhalin. Its usual habitat is among dense shrub thickets below mountain tops, meadows and screes, but in the more northern parts of its range mainly along rocky sea shores.