Common Name: Western Juniper

General Information

Juniperus occidentalis is an evergreen shrub or a tree with a rounded to conical crown; it usually grows up to 20 metres tall, but specimens up to 30 metres are reported[].
The plant is harvested from the wild for a wide range of traditional uses as a food, medicine and source of materials. It is often grown as an ornamental.
Juniperus occidentalis is presently increasing in abundance, spread and numbers of mature individuals. The southern subpopulations are stable, but lack of recruitment locally could pose problems following destructive events. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

None known

Botanical References

, ,

Range

Western N. America - British Columbia, Washington, Oregon, Idaho, California, Nevada

Habitat

Usually found on thin rocky or sandy soils[] on desert foothills and lower mountains[], also on windswept peaks[] up to elevations of 3,000 metres, where they become low gnarled shrubs[].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	18.00 m
Growth Rate	Slow
Pollinators	Wind
Self-fertile	No
Cultivation Status	Wild

Cultivation Details

Juniperus occidentalis is a very cold-hardy plant, able to tolerate temperatures down to around -25°c when fully dormant[]. The climate in its native range varies from semi-arid in the rain shadow of the Cascades (with an annual precipitation from 150 - 450mm) in the north to mesic in the Sierras, with precipitation mostly in the form of winter snow[].
Succeeds in most soils, including chalk, so long as they are well drained[, ], preferring a neutral or slightly alkaline soil[]. The plant is found in the wild on soils that are shallow, stony, and low in organics[]. Established plants are drought tolerant, succeeding in hot dry positions[].
The plant is sometimes grown as an ornamental, there are some named forms[].
Plants are slow-growing, though they can live for 3000 years in the wild[, ]. They are much shorter-lived in cultivation[], growing better in dry areas with hot summers[]. Western Britain is generally to cool and wet for this species to thrive[].
Young plants have a thin bark and are easily killed by forest fires. Older trees develop a thicker bark that can withstand moderate-severity fires. Trees are unable to resprout when top-killed, and are slow to regenerate from seed, and so are often restricted to areas where fires seldom occur naturally[].
Plants are usually monoecious but are sometimes dioecious. Male and female plants must usually be grown if seed and fruit is required. The fruit takes two summers to ripen[].
The subspecies australis (Vasek) A. H. Holmgren & N. H. Holmgren, native to California, is mainly dioecious (around 90%), whilst the subspecies occidentalis is 50% monoecious[].
Plants are resistant to honey fungus[].

Edible Uses

Fruit - raw or cooked[, , ]. A thin dry flesh[] with a resinous flavour[, ]. The fruit is sweet and nutritious[], it can also be dried or ground into a powder and mixed with cereal flours to be made into a bread[]. The blue to blue-black, ovoid seed cones mature in 2 years; they are of two distinct sizes, 5 - 10mm in diameter containing 2 - 3 seeds[].

Medicinal

Western juniper was quite widely employed as a medicinal herb by a number of native North American tribes who used it to treat a variety of complaints, especially those related to the kidneys and the skin[]. It is rarely, if at all, used in modern herbalism.
The leaves are blood tonic and laxative[]. A decoction is used in the treatment of constipation, coughs and colds[]. An infusion of the leaves has been taken by pregnant women prior to giving birth in order to relax the muscles[]. A poultice of the pounded moistened leaves has been applied to the jaw to treat swollen and sore gums and toothaches[].

The berries are analgesic, blood tonic and diuretic[]. A decoction is used to relieve the pain of menstrual cramps and to induce urination[].
Externally, the decoction is used as a poultice on rheumatic joints[].

The young twigs are antiseptic, blood tonic and febrifuge[]. A decoction is used in the treatment of kidney problems, fevers, stomach aches, smallpox, influenza and haemorrhages[].
The branches have been used in a sweat bath to ease rheumatism[]. A poultice of the twigs has been used as a dressing on burns and as a drawing agent on boils or splinters[]. A decoction has been used as an antiseptic wash on sores[].
The leaves or young twigs have been burnt and the smoke inhaled to ease the pain of headaches[].

Agroforestry Uses:

Juniperus occidentalis is an aggressive species, invading grasslands in eastern Oregon[]. This makes it an ideal species as a pioneer for restoring native woodlands and perhaps also for establishing woodland gardens[].

Other Uses

The bark is employed as a tinder and is also made into a slow match[, ]. The crushed bark was twisted into a rope, tied at intervals with yucca (Yucca species), and wrapped into a coil. The free end was set on fire and kept smouldering by blowing on it at intervals. Fire could be carried in this fashion for several hours[]. The bark can be wound around a stick and used as a torch to provide light and carry fire to a new campsite[].

The bark can be rubbed between the hands until it is soft and the fibres can then be woven into clothing[]. The bark can also be rolled into rope, coiled and then sown to form sandal shoes[].
The root fibre is used to make twined baskets[].

The essential oils obtained from the plant are used as flavouring or scenting agents in medicines, beverages, condiments, aerosols, insecticides, soaps, and men's cosmetics[].

The branches have been burnt as an incense and fumigant in the home[].

The dried seeds have been used as beads or as the 'rattle' in rattles[].

The wood is very close-grained, light, soft, exceedingly durable and resistant to rot. It requires slow and careful kiln drying to prevent warping. It is easily worked, though difficult to plane, and can be exquisitely finished. Its very durable wood can be used for special purposes such as furniture, interior panelling, toys, pencils and decorative applications but, because of its small size, it is mainly used for fencing[, , , , , ].
The wood splits easily, burns cleanly and produces little ash. It makes an excellent fuel and is also used to make charcoal[].

Propagation

The seed requires a period of cold stratification. The seed has a hard seedcoat and can be very slow to germinate, requiring a cold period followed by a warm period and then another cold spell, each of 2 - 3 months duration[, ]. Soaking the seed for 3 - 6 seconds in boiling water may speed up the germination process[]. The seed is best sown as soon as it is ripe in a cold frame. Some might germinate in the following spring, though most will take another year. Another possibility is to harvest the seed 'green' (when the embryo has fully formed but before the seedcoat has hardened). The seedlings can be potted up into individual pots when they are large enough to handle. Grow on in pots until large enough, then plant out in early summer. When stored dry, the seed can remain viable for several years[].
Cuttings of mature wood, 5 - 10cm with a heel, September/early autumn in a cold frame. Plant out in the following autumn[, ].
Layering in September/early autumn. Takes 12 months[].