Juniperus

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.

In habit, savin is a prostrate spreading shrub but can also grow as a small tree to 3-5 metres. Tolerant of extreme drought and scorching sunlight, it often grows on south-facing slopes where other trees and shrubs cannot compete. Like the other junipers, savin individuals are either male or female, i.e. dioecious, with small, oval, blue-black berry-like cones being found on the females; they are extremely poisonous. The leaves and branches also contain poisonous oils which can be smelt in the air on hot weather, and touching the shrub can irritate sensitive skins. Despite this, savin is popular as a house-plant, with several varieties on the market.

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”.

Juniper grows slowly and produces hard tough wood, with a pleasant smell. Tree-like junipers can grow to 15 metres as they are long-living; the oldest individuals in Finland are close to 1000 years old. The erect and tree-like forms were protected in the wild for many years, and even now it is to be hoped that their use is limited.

The fruit of the juniper is often called a berry although it is in fact a juicy cone. The species is dioecious, i.e. each individual is either male or female. In the three years after pollination the flowers on the females first develop into green, and then blue, berry-like cones. They have been used traditionally for flavouring and as medicine. They have high resin content so consumption should be limited.

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.

Sargent juniper is seldom grown but described as a beautiful low conifer shrub. It is a ground-creeper with long stems with dense side-branches. When young, the pale bluish-green leaves are needle-shaped but with age the branches also have scale-like mature leaves. It is usually dioecious, i.e. the male and female flowers are on separate individuals.

Sargent juniper is rare in Finnish nursery catalogues. It has spread from Mustila to enthusiasts’ collections early in this millennium when the Aboretum grew some plants from Russian seed. The variety ‘Glauca’, named in Holland by Grootendorst, is also an excellent blue ground-cover plant. The unpleasant camphor odour of the crushed leaves is an unmistakable means of identification.